Originally Posted by overlandr
Apologies if I did not make this point clear: I'm really interested in identifying the tubes not the frame
Thanks but I assume that your strategy is based on the assumption that the manufacturer is known, keeps records of frames . The manufacturer is unknown so serial number is useless AFAIK. I'm hoping there is a more direct accurate method such as markings on tubes.
How might photos discriminate between many choices (BRANDS: Reynolds, Columbus, to name a few and then many choices of their respective tube types) of tubes? Surely, they cannot
No, you were clear.
My answer is the first one.
To tell if a specific tubeset is 531, cut it apart and destructively test the tubes..... You can figure out if it is columbus by show it to an old school builder. As stated above.
The pictures were to help if it was a production frame, we could figure it out.