joe- to answer your question for future reference, the t/s and over/under stocks aren't interchangable. The trigger housing is alot smaller on the t/s (one hammer vs 2 in the over/under), therefore even if the inlet were the same, there would be a HUGE (1/4" or so on each side) space b/w the wood and and the trigger housing, and even assuming it would slide on and screw tight, it would probably crack in the first few shells b/c of lack of proper wood/metal fit.
Sorry for the long answer
Ian