Slow progress. I discovered that there was approximately 6" of seat tube frozen in the seat tube. Possibly burned down with a hot flame. Impossible to move, I finally got some caustic soda and gradually increasing the concentration got it to bubble away in the seat tube and carefully prising at the edges got the caustic soda to release the remainder. A piece of 8mm steel rod with a M8 thread put on the end fed down the seat tube with a washer and nut fixed. With the rod in a vice a few pulls on the frame got the remnants of the seat
tube out.
The bodger who did the original faking had obviously caused problems with the seat lug and top of the seat tube. These splits had been covered up with epoxy filler and paint. I re-brazed the seat lug and made a brass item to cover the seat tube split.
Another bodge was to Cyano the shifter bosses onto the brazed on points. Fortunately I have some unbonder and got them off.
Cleaning off the paint on the underside of the bottom bracket I discovered that it was stamped 55. When I removed the front forks the same number in the same size stamping at least shows they are the originals. The ball races are in a terrible state. How are ball races measured? Is it the diameter to the centre of the balls or the o.d. of the tube?
Now ready to repaint - either something from the stock of colours in the garage or try to match the original colour scheme? I don't know how they did the original fancy colour transition from red through yellow and two shades of green and then pearly white. I don't think that I can do it as well as the original.
I still don't know who made the frame. Someone may know. Beginning to like the frame so will get it roadworthy before using it as a turbo trainer frame.