Stage 1 - £30.00
FWB, HW35/77/80/85, Original 45
Deburr, spring, lube, size piston head, phosphor bronze bearing on piston.
No bearing was added to the 85 because of the piston cut out.

Stage 2 - £45.00
All of above plus fitting of solid guides.

Stage 3 - £60.00
Available on HW77 only
All of above plus piston runs on rear PTFE bearing supported by a phosphor bronze skirt and a forward PTFE bearing, compression chamber shortened to match. Choice of stroke length. Roller bearings were used to remove torque. On our ‘race guns’ we used to set them up with an Original 75 piston seal. These were very efficient but only lasted 500 - 1000 shots.

Thanks to RB for this info. Not bad for 1985.
Mach 1.5