Researching two old SF artists (Castellon & Ritter) - help!

[hegg]

Hi everyone. I toyed with the idea of asking this in the classic SF thread, but decided that the art folder might be the better place for it?

I'm doing a little research on a handful of older SF artists (trying to pin down some basic bio details really), but I'm coming up empty on two of them:

• Hector Castellon
• Bob Ritter

Does anyone know anything about these two chaps, for example are either of them still alive?! I'd be surprised if so, most of their work seems to date from the late 50s and early 60s.

Or could anyone point me in the direction of a site or archive that might have info about them? I've tried SFE, ISFDB, wiki and NNDB but the most I can find is the odd mention of some their work, no personal information anywhere.

Thanks!