I searched for Holdsworth in this thread and I think it only appears in the first post (1976 and 1982 catalogues).
There's a web page with the entire history of Holdsworth including scans of catalogues from 1934 to 1987.
Unfortunately I can't post links yet, but google for "nkilgariff" and it's the "WF Holdsworth" link.
Same site has catalogues for Claud Butler, FH Grubb, and several others.