I hope that is of any help to you.
Very helpful indeed Steve - Good reply!
I suppose one of the things that was confusing me was the sleeve-retaining-ring that Mark E pointed out in one of his photos of a disassembled motor, leading me to surmise that the sleeve was somehow meant to be removeable. Righty-oh, so you're meant to bore them out in-situ. I guess the holes in the crankcase-half for the mounting-plate would be used to somehow bolt the crankcase-half to a block sitting on the bed of the boring machine. All makes sense now.
Many Thanks,
Moby Mick.
