Scott,
I'm the lucky owner of one of Claude's former cars, the LHD 410 ("Merlin") which was the source of many fine adventures for him, and more recently for me.
I've found that my local mechanic in a (very) small town in Vermont is very capable of keeping the oily bits in good shape, and so far I have not encountered any difficulty in getting parts from Bristol themselves or US suppliers as appropriate.
Availability should be your only impediment!
Wishing you luck with your search.
Steve
Some pics if you are interested:
https://www.flickr.com/photos/107289...57637155099704