There is a place in Ft. Lauderdale, FL called MG Magic. They are reached by phone. They have tons of parts from CMC kits. Another source may be York Sports Cars in Ashland, VA. They have a website. They are kit car assemblers and used to be a good source for many MG kit parts.
I’m headed to the Import-Kit/Replicar Nationals in Carlisle, PA this weekend…I’ll keep an eye out for you.
You may want to check a good Marine supply house (West Marine, Boaters World, etc.) too. You’d be surprised of all the “kit car” stuff available at Marine sources.