"Good evening Dave, just to let you know the C15 got a proper test today at the VMCC trial at Chedworth. The engine is an absolute treat, can't believe how nicely it runs."
Comment and photo from Jon Cull January 2018 who rides in the South Western Centre.
Engine is 1967 C15 G fitted with 5TA piston giving 280cc, wide ratio gearbox and 18t crank sprocket. Electrex world ign. Built to this spec by Ratio Rebuilds 2017.