Found a new paint company that supplies linseed oil paint. Decided to experiment on my own windows.
Using traditional timber splicing repairs to frames and sills , all opening casements and sashs taken to the workshop for repairs to all joints and re-puttying. I have painted all windows in 3 coats Holkham hall old white, except for two which are in dulux exterior. Great paint to apply, looks great and easy cleaning up. The windows age range from 1850 to 1988. So far after 1 month the paint has fully hardend and seams to of adheared to both the old existing paint finish and new timber, (primed with two coats of Holkham linseed oil.) There is however some discolouring, but the plan is to put a final coat on at he end of summer. Fingers crossed it goes well and it does what it says on the tin.