First of all Roger, let's nail this myth that Jimi Hendrix played a right handed guitar strung for a right handed player. He played a right handed Stratocaster, but the strings were strung for a left handed player, ie when Hendrix played, the treble E string was the nearest string to the floor.
Libba Cotten, OTOH did indeed play a right handed guitar strung for a right handed player, and played it "upside down", as you say.