If I read your question correctly, the answer is yes, it is possible to use a T99 stock [or T38] and modify it into a shorter length "Carbine" stock. When I get back to my computer I'll post a picture of a T99 with a 17 inch barrel. O3man has made a T99 [or T38, I forget which] look like a M1 Carbine stock, a very nice conversion.
PS. Don, I hope It was ok to mention your conversion