Hi guys Many thanks for the responses.
Silver: No, the liner was not glazed, in fact, the factory hone marks are still perfectly visible for the entire length of the bore
Hobbsy: The rig is used for aerobatics - too much power is just enough! And yeah, we can't all live here...
Adrian, Homebrewer: Opinions accepted - will start with very rich setting once motor has been rebuilt. Am however just concerned that I will now probably have to install a larger fuel tank, with concomitant re-trimming et al.