RetroTech:
First, the R51 which merely updates the AC. Technically should be available during the Star League era as well, after they got around updating Prototype AC/10 to standard type.
UrbanMech UM-R51
Mass: 30 tons
Tech Base: Inner Sphere (Primitive)
Chassis Config: Biped
Rules Level: Era Specific
Era: Clan Invasion
Tech Rating/Era Availability: D/X-X-F-A
Production Year: 3074
Cost: 1 258 075 C-Bills
Battle Value: 380
Chassis: Unknown Primitive Structure
Power Plant: Unknown 75 Primitive Fusion Engine
Walking Speed: 21,6 km/h
Maximum Speed: 32,4 km/h
Jump Jets: None
Jump Capacity: 0 meters
Armor: Unknown Primitive
Armament:
1 Autocannon/10
1 Small Laser
Manufacturer: Unknown
Primary Factory: Unknown
Communications System: Unknown
Targeting and Tracking System: Unknown
================================================================================
Equipment Type Rating Mass
--------------------------------------------------------------------------------
Internal Structure: Primitive Structure 51 points 3,00
Engine: Primitive Fusion Engine 75 2,00
Walking MP: 2
Running MP: 3
Jumping MP: 0
Heat Sinks: Single Heat Sink 10 0,00
Heat Sink Locations: 1 HD, 2 LT, 2 RT, 1 LL, 1 RL
Gyro: Standard 1,00
Cockpit: Primitive 5,00
Actuators: L: SH+UA R: SH+UA
Armor: Primitive AV - 58 5,50
Internal Armor
Structure Factor
Head 3 6
Center Torso 10 10
Center Torso (rear) 4
L/R Torso 7 5
L/R Torso (rear) 2
L/R Arm 5 5
L/R Leg 7 7
================================================================================
Equipment Location Heat Critical Mass
--------------------------------------------------------------------------------
Autocannon/10 RA 3 7 12,00
Small Laser LA 1 1 0,50
@AC/10 (10) RT - 1 1,00
Free Critical Slots: 35
BattleForce Statistics
MV S (+0) M (+2) L (+4) E (+6) Wt. Ov Armor: 2 Points: 4
2 2 1 0 0 1 0 Structure: 3
Special Abilities: SRCH, ES, SEAL, SOA, AC 1/1/0
Then some weirdness and fire support. The R52 uses a 'Mech Mortar/8. It is sufficiently "low-tech" weapon so i figured it'd fit here well. 3 tons of ammo for options.
UrbanMech UM-R52
Mass: 30 tons
Tech Base: Inner Sphere (Primitive)
Chassis Config: Biped
Rules Level: Era Specific
Era: Clan Invasion
Tech Rating/Era Availability: D/X-X-F-A
Production Year: 3074
Cost: 1 089 075 C-Bills
Battle Value: 293
Chassis: Unknown Primitive Structure
Power Plant: Unknown 75 Primitive Fusion Engine
Walking Speed: 21,6 km/h
Maximum Speed: 32,4 km/h
Jump Jets: None
Jump Capacity: 0 meters
Armor: Unknown Primitive
Armament:
1 Mech Mortar 8
1 Small Laser
Manufacturer: Unknown
Primary Factory: Unknown
Communications System: Unknown
Targeting and Tracking System: Unknown
================================================================================
Equipment Type Rating Mass
--------------------------------------------------------------------------------
Internal Structure: Primitive Structure 51 points 3,00
Engine: Primitive Fusion Engine 75 2,00
Walking MP: 2
Running MP: 3
Jumping MP: 0
Heat Sinks: Single Heat Sink 10 0,00
Heat Sink Locations: 1 HD, 2 LT, 2 RT, 1 LL, 1 RL
Gyro: Standard 1,00
Cockpit: Primitive 5,00
Actuators: L: SH+UA R: SH+UA
Armor: Primitive AV - 58 5,50
Internal Armor
Structure Factor
Head 3 6
Center Torso 10 10
Center Torso (rear) 4
L/R Torso 7 5
L/R Torso (rear) 2
L/R Arm 5 5
L/R Leg 7 7
================================================================================
Equipment Location Heat Critical Mass
--------------------------------------------------------------------------------
Mech Mortar 8 RA 10 5 10,00
Small Laser LA 1 1 0,50
@Mortar 8 (Airburst) (12) RT - 3 3,00
Free Critical Slots: 35
BattleForce Statistics
MV S (+0) M (+2) L (+4) E (+6) Wt. Ov Armor: 2 Points: 3
2 1 1 1 0 1 0 Structure: 3
Special Abilities: SRCH, ES, SEAL, SOA, IF 1
Then the main event itself:
The R53, armed with 5 RL15s and and 8 RL10s. Has 4 extra heat sinks.
This is a pure ambush unit, so the low armor is not a concern really.
UrbanMech UM-R53
Mass: 30 tons
Tech Base: Inner Sphere (Primitive)
Chassis Config: Biped
Rules Level: Era Specific
Era: Clan Invasion
Tech Rating/Era Availability: D/X-X-F-A
Production Year: 3074
Cost: 1 359 475 C-Bills
Battle Value: 490
Chassis: Unknown Primitive Structure
Power Plant: Unknown 75 Primitive Fusion Engine
Walking Speed: 21,6 km/h
Maximum Speed: 32,4 km/h
Jump Jets: None
Jump Capacity: 0 meters
Armor: Unknown Primitive
Armament:
5 Rocket Launcher 15s
8 Rocket Launcher 10s
1 Small Laser
Manufacturer: Unknown
Primary Factory: Unknown
Communications System: Unknown
Targeting and Tracking System: Unknown
================================================================================
Equipment Type Rating Mass
--------------------------------------------------------------------------------
Internal Structure: Primitive Structure 51 points 3,00
Engine: Primitive Fusion Engine 75 2,00
Walking MP: 2
Running MP: 3
Jumping MP: 0
Heat Sinks: Single Heat Sink 14 4,00
Heat Sink Locations: 1 HD, 2 CT, 2 LT, 2 RT, 2 LL, 2 RL
Gyro: Standard 1,00
Cockpit: Primitive 5,00
Actuators: L: SH+UA R: SH+UA
Armor: Primitive AV - 58 5,50
Internal Armor
Structure Factor
Head 3 6
Center Torso 10 10
Center Torso (rear) 4
L/R Torso 7 5
L/R Torso (rear) 2
L/R Arm 5 5
L/R Leg 7 7
================================================================================
Equipment Location Heat Critical Mass
--------------------------------------------------------------------------------
5 Rocket Launcher 15s RA 20 10 5,00
Small Laser LA 1 1 0,50
4 Rocket Launcher 10s RT 12 4 2,00
4 Rocket Launcher 10s LT 12 4 2,00
Free Critical Slots: 21
BattleForce Statistics
MV S (+0) M (+2) L (+4) E (+6) Wt. Ov Armor: 2 Points: 5
2 2 1 1 0 1 0 Structure: 3
Special Abilities: SRCH, ES, SEAL, SOA
And then something more elaborate: The R55. This thing has LAC/5 with two tons of ammo (you know, for special munitions) and a pair of RL10s for main weapons, and the small laser is augmented by a pair of MGs. Also, the jump jets are back, since this is kinda intended to be an option for the actual, proper UrbanMech.
Also has more armor though admittedly doesn't have ideal armor distribution.
UrbanMech UM-R55
Mass: 30 tons
Tech Base: Inner Sphere (Primitive)
Chassis Config: Biped
Rules Level: Era Specific
Era: Clan Invasion
Tech Rating/Era Availability: D/X-X-F-A
Production Year: 3074
Cost: 1 292 525 C-Bills
Battle Value: 429
Chassis: Unknown Primitive Structure
Power Plant: Unknown 75 Primitive Fusion Engine
Walking Speed: 21,6 km/h
Maximum Speed: 32,4 km/h
Jump Jets: None
Jump Capacity: 60 meters
Armor: Unknown Primitive
Armament:
1 Light AC/5
2 Rocket Launcher 10s
1 Small Laser
2 Machine Guns
Manufacturer: Unknown
Primary Factory: Unknown
Communications System: Unknown
Targeting and Tracking System: Unknown
================================================================================
Equipment Type Rating Mass
--------------------------------------------------------------------------------
Internal Structure: Primitive Structure 51 points 3,00
Engine: Primitive Fusion Engine 75 2,00
Walking MP: 2
Running MP: 3
Jumping MP: 2 Standard
Jump Jet Locations: 2 CT 1,00
Heat Sinks: Single Heat Sink 10 0,00
Heat Sink Locations: 1 HD, 2 LT, 2 RT, 1 LL, 1 RL
Gyro: Standard 1,00
Cockpit: Primitive 5,00
Actuators: L: SH+UA R: SH+UA
Armor: Primitive AV - 85 8,00
Internal Armor
Structure Factor
Head 3 7
Center Torso 10 13
Center Torso (rear) 5
L/R Torso 7 7
L/R Torso (rear) 3
L/R Arm 5 10
L/R Leg 7 10
================================================================================
Equipment Location Heat Critical Mass
--------------------------------------------------------------------------------
Light AC/5 RA 1 2 5,00
2 Rocket Launcher 10s RA 6 2 1,00
Small Laser LA 1 1 0,50
2 Machine Guns LA 0 2 1,00
@Light AC/5 (40) RT - 2 2,00
@MG (1/2) (100) LT - 1 0,50
Free Critical Slots: 32
BattleForce Statistics
MV S (+0) M (+2) L (+4) E (+6) Wt. Ov Armor: 3 Points: 4
2j 2 1 1 0 1 0 Structure: 3
Special Abilities: SRCH, ES, SEAL, SOA