O-ring kit for Duo-fast TI-3118 + TI-3118A Price includes shipping in the US
I should have the bumpers for these in the future, email me if you need one.
Seal, part #17, 1015035, SM-111-2 (Cylinder Seal)
Complete O-ring kit
Also have bumper available below #22, 1015038, SM-110-5
Pictures and rebuilding video below,
O-ring kit for the Senco FramePro + Aftermarket Cylinder Seal # BF0203 + Free Shipping in the US