I think I have collected quite a bit of useful knowledge and skill by working on physics for 1967 Endurance cars. It all should apply nicely to XJ13, looking forward to update physics. I don't remember what exactly the now available model is, but I will probably only attempt some texture and shading improvements in near future.
Meanwhile I am getting used to Blender 2.8, and it is fun. I have never played with Cycles rendering engine, I like Evee a lot, but I just started using cycles, and the improvement is amazing to me. Here are some renders that goes from almost none to increasing intensity lighting. I did series of renders with rather low image size and rather low sampling rate, so it didn't cost ton of time. In this link:
https://imgur.com/a/1q2o2lF
And just one render for show.