I can't remember Holdsworthy using crimped chainstays, which makes this looks like a frame from a largish maker, with a gas hole under the bridge behind the bottom bracket. Then 2 small bits of tubing tacked on the bottom bracket for cable guides looks a bit of an after thought.
It looks about 1975/80, it's not nervex, whose lug sets were pressed and welded, and were very strong and light. The bracket shells had identity stamped into them.
Your 27.2mm indicates butted tubing.
The front fork end domes and slots do not look quite standard, and the rear end seat stays are brazed very low. Extra work like this points to a small builder. It looks decent though. So contradictions all round.
Not much help.
How about a competition to suggest a classy but fictitious name?
Possibly built by an immigrant who learnt frame building in Italy?
It looks about 1975/80, it's not nervex, whose lug sets were pressed and welded, and were very strong and light. The bracket shells had identity stamped into them.
Your 27.2mm indicates butted tubing.
The front fork end domes and slots do not look quite standard, and the rear end seat stays are brazed very low. Extra work like this points to a small builder. It looks decent though. So contradictions all round.
Not much help.
How about a competition to suggest a classy but fictitious name?
Possibly built by an immigrant who learnt frame building in Italy?