Wait, we talkin just knobs for standard-sized pots, right? (at least I would think a T3 has standard pots).
Have you tried the usual suspects: Allparts, WD Music, Stew Mac, and the like? Determine whether your T3's pots are splitshaft or solid and order friction-fit or set-screw accordingly. Lots of vendors out there beyond the three common ones I've mentioned.
Edward