Grab a cup of coffee, start going through [url]www.classiclightweights.co.uk you should find it there, if it is British that is.
Hilary Stone The site for Classic and Vintage bicycles and their parts, email Hilary, I did with questions on a incredibly rare frame I have, he got back to me within 4 days with was great, the Brits were in a league of their own with lightweights 20's-50's
try not to spend too long looking at British lightweights because you will end up wanting 1 or 20