Jim,
I have had good luck with finding service and repair manuals on eBay. There are several suppliers for parts in the USA. Where in the world are you located?
rubbers. depending on where you’re located, If you cant find the OE replacement through SNG or the suppliers Mr. O’Connor suggested then I’d start looking at local industrial suppliers or online suppliers such as McMaster Carr
automotive sealing products
In the USA www.steelerubber.com
In the UK
I’ve found if you go to a general supplier, you can get the same stuff for less money than if you get from a “Jaguar” parts house. Especially if the parts are hard to come by like trim.