MiloFrance,
Your Holdsworth frame with a six digit serial (#005933), according to Dave's prediction graph, would be placed at 1977. This is a helpful number as there had been a gap in frame numbers in that range.
Armed with the info of a frame predicted to be 1977'ish one can go to online resources to confirm and source the model.
Looking at catalogues from Kilgariff's site this frame would fit as the starter Holdsworth model - 1977 Equipe. He has a 76 catalog and a 78 which appears to be the last year of production.
Frame would have to be plain gauge and that vintage would have a straight rear brake bridge. Pic? A BB cable guide for RD and a cable stop for FD is typical. Apparent non parallel geometry I suspect is camera generated. need a side on view.
Randy(?) who posts to this forum has a very useful website and one of his "England" bikes is a "70's" Equipe. A great example.
FINDING THE HOLDSWORTH EQUIPE
Doug