This is a Serbian web site (maybe a google translate will help) with info on armored vehicles used in this region. There is a article with some pics on this tank. Not much help, sorry. Check Slovenian modellers web sites - we were guiding Slovenian fellow modellers when they made workarounds - they probably published something.
It is not a straight conversion from T43, and it had US 76mm gun, as well as OS .30cal MGs...