In addition to Ebay, there is a few companies which provides new or refurbished parts... Post them here
gaskets for the 3.5 litre york http://www.gasketsforclassics.co.uk/classiccomm.html
pistonrings for the york http://www.hamenz.com/models/FORD.htm (allmost in the bottom are the 0509 engine these rings will fit the 2.4 and 3.5 york
-nelson stokes in camelford cornwall can make up flexible rubber brake hoses to pattern(can anyone help with contact info?)