Tom,
I have considered a Canon S70 used, I buy a lot of used gear without problems, basically from KEH, Adorama and Cameta....good luck with all of them.
The Gowlandflex cameras are still available from Peter, I think he is over 90 years old now.. He was my mentor when a young photog in the Navy, I actually met him in L.A. at a show when I was about 21 years old (wish I could go back there again)
. Without a doubt one of the best studio glamour cams ever built.