The cold war export T-72s are interesting beasts. Since they were built under license in several nations and were aquired by several others with the skills to fiddle with them there is scope for a considerable variation, though probably not massive in terms of actual performance.
From what I have understood there were three basic model
1) An initial version made available since 1979. It had a cast steel turret and a composite glacis.
2) T-72M, introduced during the80's. Same armor scheme as the above but with improved systems (laser instead of optical rangefinder, more accurate gun etc).
3) Finally the T-72M1 also introduced in the 80's. Composite turret and strenghtened glacis.
Several subvariants probably have existed. T-72M may have received additional steel glacis plate (done inEast Germany IIRC)
to be at least partially brought up to T-72M1 protection standards. Basic T-72 may have been upgraded with laser rangefinders
and improved systems. Some manufacturers may have fiddled with T-72M1 front turret cavities composite fillers etc. Some locally assembled iraqi
T-72M1 Assad babylon appear to have appliquè armor on the turret front. This of course before the end of the cold war. All the sort of upgrades
may have been carried out since then (typically along the lines of ERA being fitted, better FCS etc.)
Some food for thought in the following links
http://img392.imageshack.us/img392/1...striderpz7.jpg
http://www.angelfire.com/mi4/armania...t72/T72M1.html
http://208.84.116.223/forums/index.p...cavities&st=20