Frying pan into the fire.

[Murphyv310]

Pleased to report that all the cleaning of gum, varnish and sludge has been a total success. The big thing was the choked oil way in the cam cover. I don't see any reference to this oil way online and it's actually hard to see especially with sludge on the cover. I'm just wondering how well this is known about, considering it lubricates the chain it could well be the cause of premature chain and tensioner failure.
I've been stripping engines all my days and have found many little things that are not mentioned in workshop manuals, both official and the likes of Haynes. At least I've now a nice quiet engine which is pulling very nice indeed.