I own a T3lite and when I wanted to replace the synthetic stock with a boyds stock they made stocks for the original T3 but not the lite so there is a difference. I took mine out of the safe to check and there is no indication that it is a T3 Lite versus a plain or older T3, I would send a email to tikka with your serial number and ask them.
Yep. The stock. Fiberglass-reinforced all-black polymer on the Lite. Wood for the discontinued plain T3.
Boyd's lists the T3 and T3 Lite under Tikka not Sako.
No difference in the stocks. I've had both and they interchanged. When buying aftermarket parts they often only list one part name or number if parts are interchangeable.