I got this one a few days ago, I don't know anything about it. It's a 3 speed Celtonia. That's about all I got on it. I can't find anything about it online. I posted a thread in the bike I.D. section....
Looks just like a pre-1960 Hercules. They were also made in Birmingham. The fork crown and frame lugs are identical, so maybe it was one of them with a different brand name. The hub shell should have a date code on it, 2 digits for year, and a digit or 2 for month. 11 71 would be Nov 1971 build date. If that's the original hub, it should be 1959 or earlier.