Thanks Ogre. You can get a cap from any XJ6 I believe up trough ‘86. Here’s one on eBay for $15.
https://rover.ebay.com/rover/0/0/0?m...2F232350728215
I made a cardboard template pretty much like this but it wasn’t too difficult, just had to make sure it flowed with the contour of the fender and was positioned in such a way that it wouldn’t hit the bed roll when it was open. I am by no means a metal fabricator nor have any experience doing anything like this, but with the help of countless videos on welding I was able to make it work. Bondo and body filler are my friends! Lol!