The early TR6 had an interior courtesy light at the back of the gearbox tunnel just a year of the cargo shelf. Mine was missing when I got it, but after a few drives home in the dark I realized that it would be really nice to be able to see the dashboard and the ignition switch in the dark. 

Reproduction parts are all available to replace this, but the mounting plinth is $50, and I found these bright little 12v LED light bars at Menard's, so why not make one?

Since I already had the light and could easily get a switch from my handy local surplus store, i decided to try designing a mount for the light myself and printed it on my 3d printer. 

The print came out great, other than an odd layer shift toward the end. I wired it up with bullet connectors and installed it on top of the gearbox tunnel carpet with the hook side of some Velcro tape.

Here’s the final light installed, a bit crooked in this photo:

And the light turned on:

It's plenty bright enough to light up the dash, and i'm using the other one from this pack as a replacement for the trunk light. I may cover the plinth with some sort of fabric if i can find something that goes well with the carpet, but it's hidden enough behind the seats that it's a low priority upgrade.

I've uploaded the stl file for this on Thingiverse, that page also has a link to the original drawing in OnShape so you can customize for a different LED strip or switch hole.