The forks were pretty clean, so, after a final rub down with some 320 grade wet and dry and a whipe with a clean rag & white spirit, I put an immediate acid etch primer coat on. This seemed to go quite well.
A second coat had it ready for the colour.
The frame was quite badly pitted and still had some surface rust. I'd given it a good sanding but decided to treat it with a rust treatment. Once this was done it was ready for the primer.