Hmm, all the years are at the default 3145. Do you have any idea when certain designs should be?
Ok, comparing what I made based on the XTRO and your MML files, I've found a few other discrepancies between the XTRO and the MML files.
On the Alexandria Coreship, the number of docking collars, cargo bay mass, ASF bay doors, 1st, 2nd, and 3rd class quarters are all different in the XTRO. In fact, the MML file doesn't even have any steerage class locations. The total mass and crew compliment is also different.
The ammo on the Hadron are all set to "fixed".
On the Hunter Jumpship, the loss of the life boats seems... harsh.
From my understanding of the rules, the Model 98 should have 12 gunners and only 11 officers. There's also not enough quarters for all the BA marines; there's a total of 73 non-officer crew and marines, but only 60 quarters for the non-officer crew.
The Wusun MML file is misspelled to "Wuzun".
The Dyrnwyn A in the XTRO has a remote sensor dispenser, but in the MML they have a Micro PL.
The Gatekeeper A in the MML files has DHS locations that don't match the XTRO. Ammo is found on the LT in the MML files, but not listed there in the XTRO.
The Gatekeeper C in the XTRO file has only three jump jets and nine extra DHS, while the MML file has four jump jets and seven extra DHS.
The Haze D lists a DHS in the CT and RT, but the MML file has them in the legs.
The Hellion Z, Savage Wolf Z, Nova Cat Z, Grand Summoner Z, and Mad Dog Mk IV Z, and the Adder Z are missing in the MML files. As are all the vehicle refits.
Compared to the PDF files you posted earlier (that I somehow missed), I was surprised that you didn't put two of the LRMs on the Mars into sponsons. I thought that's what was meant in the XTRO writeup about moving them to the side.
The Kharon features a hand and lower arm actuator on the right arm in the MML file, despite the image pretty clearly lacking those.
The Rotunda C with the rocket launchers can actually get a 10/15 speed with a fuel cell engine.
Anyway, if you're interested, I fixed up most of the files. I've also renamed some files to match up with MegaMek naming conventions, and also to ensure that the variants of existing designs will automatically load up the original's fluff image (if those are being used).
I've also included a text file with all the perks. Just paste it into your CustomQuirksOverride.txt file.
http://www.mediafire.com/file/4ugc8m6wrn5ec0v/XTRO_Society.7z/file