I believe that the T3 had 23mm bars... Mine are from Sway Away. I orginally was running adjustable spring plates and had to switch to a shorter (earlier) T.B. so upgraded to the 23mm at the same time. If I were you I'd pick the springplate/a-arm combo that is in the best shape and go with it, unless you want to run a heavier T.B.
I hope that I'm helping...
Cheers,
Dave