I specialise in XJS second-user Jaguar parts, grubbed and logged from good-quality cars. Also, to a lesser extent, parts from late Jaguar XJ40, XJ12, & X300 models of the 1990's.
XJSstuff has thousands of used spares, catalogued on computer by Jaguar part number, and so is a quirky source for obsolete and hard-to-find XJS used parts. I do not have a yard or donor cars to pick over, but operate on a email/mail order basis.
However, I am in the process of running down stocks and closing the business so, although I still have 7000 parts, it will be worth enquiring about your requirements for some time to come. Sadly the rarest parts are always the first to go, but few people realise yet how rare XJS parts are going to become.