Hi Dave, thanks for your concern, Its a 58 splitty. But have sorted it now
The front clyinders are the same size bore as the 64, so cleaned up the bores, and bought 4 later type, and fitted the pistons only. total cost about £30. (heritage want £65 per clyinder ) rears were no problem at £9 each. so all sorted .. and just made it to the NEC classic show with MOT