Currently - No,
But once i get back to my modding station, i will see if any ideas hit me from left field.
The only idea I have at this point in time is for you to modify the dds files for the game.
when you navigate to \Gratuitous Tank Battles\data\bitmaps\units\mech\ you will see a whole pile of folders.
In the folders HM,LM & MM you will see 3 files (for example)
Rename the HM_1_legs.dds to somthing like HM_1_legs.bak
then make a copy the HM_1_legs_512.dds and call it HM_1_legs.dds
Rinse Repeat for all directories.
Run the game again and see if it helps