That list of "Holdsworth" builders spans several decades and includes builders at factory and Putney shop. For instance not aware of Hurlow ever building for "shop". Collard, Quick, Bird and Roberts certainly did according to Kilgariff.
Geometry looks "tourer".
2 sets of bottle bosses support this although perhaps later ad-ons at time of repaint? Are there actually braze-ons?
A clip for RD chain-stay cable guide is unusual as even when braze ons were frowned on c.'70 most frames still had a rear cable guide. Original on top of chain stay perhaps removed? Makes me wonder if hole in bottom of BB was originally for a grease nipple? Is it threaded?
Kit spans several decades.
Pics of rear brake bridge will be good.