Well, final update from me on this I guess, I had the treble part of the pick rewound (WD Music) as it was dead, its now been re-fretted and setup (Andy Crockett) and I've replaced the tug-bar. Strung with La bella's.
regarding Pickguardgate - I went with the black scuffed up and stained with Briwax.
Probably not to everyone's taste, but I really like the result. For a '75 it plays great, sounds as a P should, is fairly light with as many original parts as I could recover. If anyone has a rusty screw they are willing to post for the pickguard above the tugbar, please give me a shout. Oddly (considering the condition of the bass), the screw is bothering me 😆