I've never *heard* of Manly Wade Wellman or anything he (?) wrote :-)
(Please tell me that Manly is a male and that no progressive-thinking
parents named a girl "Manly".... Oh, that's a relief, I just did a look
in Wikipedia and he was a male. Quite a distinguished fellow too by the
sound of it. I've never come across his name before though, as far as I
can remember. Obviously, my knowledge of SF has some gaps in it!)
But thanks for the suggestion! Once Door Into Summer was mentioned, I
realized that was *exactly* where I heard of Leonard Vincent and the
idea that he might have been sent back into time and become Leonardo da
Vince. I'm still kicking myself for not having recognized it since Door
Into Summer is perhaps my favourite of the "smaller" Heinlein novels (as
opposed to the "big" ones like Stranger in a Strange Land and Time
Enough for Love).
--
Rhino