ok been awhile, sorry about dead images , my google account got disabled so have moved images.
ordered dad a 32mm cutter of fleabay , this was to big to actually fit in is mill , so he modified it ,
Then he cut a big peice of would at the correct angle for the piston to be mounted to ( to reflect valve angle , yes we think both inlet and exhaust are a little different on angle but not enough to worry)
also we are doing one size cutter for inlet and exhuast valves.
Test cutting went well , valve centres where marked by sending tool down through valve guides on head and marking piston.
now tested on old piston , block and crank need machining now , so new +20 pistons can be fitted ,marked and machined.
As my dad does not have access to allot of equipment , he finds it easier to make smaller parts , so for all the seal locations , he will machine small round seal locators that are they easily aligned to the shaft they are made for ,
see below for example of crank pulley seal. ( also visible is spacer for lower cam pulley