Another good source is called “MG Magic”. It’s a couple of old guys in Miami, Florida that have parts for MGTD kit cars, especially CMC/FiberFab stuff. I’ll try to find the phone number, they have no website.
Another source for these parts may be York Sports Cars in Ashland, VA. He is a kit car assembler. He’s hard to get a hold of sometimes, but is very knowledgeable. http://www.yorksportscars.com