could there be indentations in the fork bearings?

Dish washing soap is not good. It contains a lot of salt, causing rust. You must neither use it to mount tyres for the same reason.

I'm rather sure, it is cycle thread. 1/4 x 26TPI.

My main concern now is, that I need some 3 mm rivets for a project. But if the need is strong enough, I can turn them on my lathe.

It seems to have a thick compressionplate under the cylinder.

No prefix on neither engine nor frame number?

In 1959, when I was a poor apprentice, I restored an Ariel MF. One of the flywheels had a crack from the big end out to the edge. I turned some mms off the diameter of the flywheel, and made a steel rim from flat iron, which I turned to size and shrank onto the flywheel. Then the crack was under con...

The framenumber normally is just above or near to the cap on the oil tank. They made the oiltank higher and to the rear to clear the carb so they welded a support on the number. I can see, what you mean. But with a little bit of luck you could be able to see it, by removing the oiltank. Otherwise w...

The framenumber normally is just above or near to the cap on the oil tank.

Who would sell that?