I understand a few errors crept in because the OOB underwent major changes last year, so I'll keep this focused on ironing out these. I've also tried experimenting to see what stuff the AI picks and made a few according suggestions.
UNITS
017 - From what I can tell this gun wasn't used by the Yugoslavs at all. I think this is a hold-over back from the original Steel Panthers. What the Royal Army actually used was the 37mm KPUV vz 37 AT gun (see Czechoslovak OOB), which can have the same start date and its end date can be extended to 12/44 since it was used by the partisans, too.
Here's a couple of photos of the gun in question:
http://fototeka.sabh.hr/FotoAlbumi/Fotografija/1212
http://fototeka.sabh.hr/FotoAlbumi/Fotografija/179
Note: the 25mm gun currently appears in scenario 032.
024 - start date can be changed to 10/44 (I goofed last year - the first ones were captured and put in use during the liberation of Belgrade)
033 - I think this should be the Breda M.37 (which is actually pictured), not Breda M.30. Here's a photo of an actual MG used by the partisans:
http://www.lokalpatrioti-rijeka.com/...e.php?id=19815
074 - radio code can be set to 2, they were far more common than the T-34/76s (the latter were really just a handful of captured vehicles)
118 and 119 - unit class should be changed to 234 (5-man squads are intended for the partisan cavalry formations)
283 - Weapon in slot 1 should be 14.
335 - orphaned. Unit class should be 6 (alternatively, you could make a Heavy AT Gun formation, but I think this is simpler).
441 - It has 8 crew and radio code 22. I believe it should be 4 crew and radio code 2?
455 and 456 - I recommend unit class to be changed to 19. This is because the AI likes to take units from class 19, and will choose unrealistically large numbers of Stuart-PaKs. This change will help alleviate the problem somewhat.
459 - end date should be 4/41 (fall of Yugoslavia).
FORMATIONS
014 - start date should be 11/44, to accomodate unit 455 (see above).
017 - start date can be changed to 1/44 - AT gun platoons existed already at that time.
025 - Template unit should be 15 (Heavy Truck). Right now it is 13, which is actually a medium truck.
059 - start date should be 11/42, to accomodate some guns that appear then.
148 - end date should be 4/41 (see above).
There's no MG platoon for 1/45-12/46 - I think it would be nice to have one for convenience sake. It would consist of 3x unit 37 (Maxim HMGs)
WEAPONS
089 - wasn't used, should be replaced with RPG-40.
37mm KPUV vz 37 AT gun and Breda M.37 will need to be added (see above)
That will be all for this year.