"T-72S : Export version, conflicting data - some sources state export version of B, some state it's A/M1 with B FC and ERA which would mean weaker armour than 72B."
I am pretty sure that T-72S is T-72B, give or take a few details.I mean, with only light era and no thermal sight in the 21st century it is already enough of a tracked coffin without having to go further back to the T-72A armor scheme.
"T-72BM : Newer composite, better FC"
AFAIK it was basically a T-72B with Kontakt-5.The improved
FC/passive armor/everything was the T-72BU.Or T-90 as they call it now.Or so I heard at any rate.
"Romanian TR-125"
That thing never went in mass production AFAIK.If you get into things like prototypes and modernization packages there are enough to fill an encyclopedia and a new one popping out every week.My favourite was the T-72S with Kaktus ERA which was proposed for Yemen.
Here is a good source I was recommended for some armor values:
http://www.hot.ee/vsevolod/T-72values_eng.htm