Thanks Keith, in an ideal world I would have put in a Mark 2 engine, but I had to work with what I could get. The frame, tinware, and wheels are all 1958, while the engine is 1952. I think the Wedgewood blue colour came in either 1953 or 1954. It’s now running perfectly but I can’t take it out under the current lockdown in the UK (unnecessary journeys and all that).
Handling is better than my mark 2 with Anstey suspension, although I haven’t really pushed it hard yet.
Here is a picture of the crank, looking through the oilway, obviously the side galleries were cleaned out too.
Square 4 mk1, Square 4 mk2, Colt, BSA C12.