Originally Posted by
Sixty Fiver
...Cranks appears to have a 57SC outer chainwheel so that pushes the dating up unless that chainwheel was a replacement... the bike is a bit of a time capsule of what was good and right in the 1950's...
57sc cranks had a forged spider together with the arm, so I think that's a complete 49d crankset fwiw.
I agree it seems English, and with much of the file marks previously covered by paint.
As for the rear derailer, I have an old Gran Sport mech that also has the hex cable adjuster and a 7mm spring cover cap. I'm also wondering what year that is from.