Proxy Recommendations for Miniature-less Figures

[Mendrugo]

I'm running a campaign that's digging deep into the forgotten underbelly of MechWarrior 1st Edition and the Vehicle Annex for units, and would love suggestions for good figures to use as visual approximations for the following:

1) Corx Mobile Tunnel Miner


Best approximation I've found is an old GoBot toy - Screw Head:


Anything more on target?

2) GS-54 Guard SecurityMech.  All we know of it is that it has four legs and two machine guns.  Perhaps a Revenant drone?

3) Mining Robot - has treads and a bank of eight small lasers on the front.

4) Large Agricultural Robot - described as 160 tons and having a combine harvester attachment.  Planning to "Mad Max" it up with bolted-on missile launchers, etc. 

5) Silverfin coastal cutter - looking for something that'll fit in a couple of BattleTech map hexes.  Most naval model kits I've found that look close are way too huge.

6) Skimmer - planning to use Savannah Masters as a stopgap (since they're canonically just Skimmer frames with extra armor and a bigger fore laser), but if there's anything more hover-cycle-ish out there:

[Weirdo]

5) Silverfin coastal cutter - looking for something that'll fit in a couple of BattleTech map hexes.  Most naval model kits I've found that look close are way too huge.

Google "PT Dockyard". When you're there, look in the section for modern 1/700 fast attack boats. I don't have any yet, but I plan to order some of his Turya Project 206M Torpedo Hydrofoils for this exact purpose. Unless my math is way off, they should scale very well for this, needing almost no work except maybe to hack off an aft turret or something.

[Schottenjaeger]

5) Silverfin coastal cutter - looking for something that'll fit in a couple of BattleTech map hexes.  Most naval model kits I've found that look close are way too huge.

6) Skimmer - planning to use Savannah Masters as a stopgap (since they're canonically just Skimmer frames with extra armor and a bigger fore laser), but if there's anything more hover-cycle-ish out there:

For 5) I found some Matchbox boats, which I cut down to a more reasonable 6mm size. Still mounting a deck gun and a missile rack, but they have space to work with and nice lines.
As far as 6), there was a very nice vehicle in a capsule toy/gashapon set that came out a few years ago from CMS - Fang of the Sun Dougram, series 3. It's in 6mm and it's  fairly easy to pull the MG and gunner out for a nice little hovercycle. They come as part of a set with some other little softskins.