It appears there are only "6" D-licenced engs in the UK!!!!! I spoke to one of them and he was happy to inspect the engine internally and give a new cert for it, although he currently has a backlog of 50 engines for rebuild. The engine is brand new (not zero timed) and therefore, by his reasoning, not going to be corroded by combustion products. Just a case of getting through to the PFA with these recommendations.
Fargoo, where did you get the figure of £3000 from? Mags and carb would cost the best part of £2000, wouldn't they?