greg,
there actually is a version of "Foggy Mauntain Breakdown" played on tenor banjo on a cd named "Peter`s Banjo Greetings - Hot Stuff Petrol" by Peter "Banjo" Meyer. Not on the mans website, though, which is here:

http://banjomeyer.de/onlineshop/index.php?cat=c2_Peter---Banjo---Meyer.html&XTCsid=6c3f2af69b2e31d01c7adf0c82b91c90

I still prefer the 5-dtring version....

Best
Erenest