Hi Pete,
Found a bug in the Finnish list for CWC in the online generator.
Set to 1957 for year, and BMP-2 is available as an ATGW asset, and the RAKH 89 rocket launcher is also available as off table support. BMP-2 is later I know (but not when) and the RAKH is 89 onwards (I believe!).
Oh yes, and it shows T-54 available and they weren't delivered until 1960
Stug III/IV with long 75 should be available up to 1966, T-34-85 & T-34 with 76mm to 59, as well as various marks (but probably coverable under one awful stat line) of T-26's.
Probably all limited to 3 per 1000 and [9] total? Dunno how worth it adding these are, am not convinced many people play early cold war Finns but thought I'd say for reference whilst you're not doing anything else