classic motorcycle forum

Like "Lucas" electrics - now supplied by Wassell and originated who knows where - but not Great Charles Street. The trade names are bought up by shysters to give a veneer of respectability.

Have you tried the chain man? He lists a 1/2" x 3/16" 415: https://the-chain-man.co.uk/chains

Actually I thin k the change from the old style gearbox to the laydown box had more to do with the footrests .......the WW2 bikes had two footrests the same,laydown box has the RHS footrest  with bends and loops to clear the gearbox.

The upright gearbox top mounting was a "fork" that engaged with a rearward lug from the seat tube. These were notorious for fracturing if the bolt wasn't kept tight. The laydown was much better in this (and other!) respect(s) as it had a solid top lug that sat between two engine plates.

Mostly true. However years ago I put an ES2 engine in a 16H rolling chassis and had no issues with frame or footrests - but had to have someone chop out the underside of my freshly painted and lined tank!

Funny that the people who built bikes at Bracebridge Street etc managed not to break things despite not having torque wrenches. I have one but very rarely use it as I think my "mechanic's feel" is good enough. And the only fixings I've ever broken have been ones irretrievably rusted in place.

I'm not sure why combination spanners are denigrated. I find them useful in the workshop as the flat ring end gets where the usual cranked ring spanner won't. For example, the cylinder base nuts (pre-UNF) on small Triumph twins are tricky beasts. I just ground a small amount off the outside of the ring end of a combi and it worked perfectly.

It's a shame that the OP who seems to be a capable person seems so touchy. But I'm sure we'll limp along without him. The population here may be small but is exceedingly knowledgeable and helpful.