Members,
Thanks for the flattery, but I do not claim to be an expert. What I have learned re Holdsworths and Claud Butlers has been gleaned from sites I am sure most are aware of as Norman Kilgariff's site, Classic Lightweights and Classic Rendezvous. I did recently spend a good amount of time collecting a "pile" of mainly Holdsworth variant Claud Butler numbers trying to brake the "Enigma Code" and in process make sense of my new Claud's serial number. I have summarized everything I have learned in the dissertation under the following Flickr photo:
https://www.flickr.com/photos/767624...7648723035788/
You should be able to fine tune your frames' age estimates. However difficulty arises with some serial numbers that do not fit into any recognizable pattern and it is impossible to answer without conjecture. I am interested in acquiring frame numbers especially Holdsworth variant Claud's with accurate pedigree. Some of the answers may become clear with time.
Cheers, Doug