Here is a review/comparison of the A7, the 85, and the T3.
http://www.biggamehunt.net/sections/Hunting_Gear_and_Products/Sako-A7-Review-09090804.html
The A7 has the plastic shroud, triggerguard, and magazine like the T3, but the 3 bolt lugs and the open top receiver like the 85. The stock is more like the T3 than the 85, and all 3 models use the same barrels.
The T3 uses one action for all cartridges, with the use of bolt stops for different lengths.
The A7 uses 2 actions, one for short cartridges, and one for standard and magnum cartridges, again with different bolt stops.
The 85 uses 5 different actions, each tailored for various cartridge lengths, ie: 223, 308 based, 30-06 based, wsm, and full length magnum cases.