Italy: P.43 Bis, P.43 Ter, & P.44 Pantera with alternative "late-model" machine guns (unhistorical)
Poland: 45TP Habicha with alternate (simplified) DShK mount
UK: Centurion 7/1 with standard cupola-mounted .30-cal MG (same as Centurion Mk1/Caernarvon)
USA: T30 with roof-mounted MGs only (no spare .50-cal on turret rear)
USSR: T-54 ltwt. with twin-KPV mount (from Obj 705A)
Any included vehicles, which have oscillating turrets (i.e. AMX 13 105, Kranvagn, etc.) may not display large projection decals correctly (due to a bug I have not been able to solve yet). Everything else (paint, standard emblems, inscriptions, camouflage, etc.) work exactly as they should, however.
More vehicles are in the works! Stay tuned for more updates.
IN-GAME PREVIEWS NOTE: Not every vehicle shown; Check the above list!
EDIT (6. Aug 2019) - Turns out taking preview images for every single vehicle (being that there are over 100 vehicles included) can be rather difficult/time-consuming. (Who would've thought?) I am considering dumping a bunch of preview images into an Imgur gallery, but for the time being, you will have to see most of the dakka in-game on your own. My apologies.
Still, I have some random images from earlier releases below, if you'd like to check them out.
China: Type 58
France: AMX 13 57 / GF
France: B-C 12 t
France: AMX 13 90
Germany: Pz. IV H
Italy: P.43 bis (alternate version shown, included as add-on)