In the end I bought the 350/11 new through B&H - possibly one of the last that Schneider has in stock since it had to be special ordered from Germany. I think it was a wise purchase given the scarcity of the lens on the second hand market and its focal length / weight / filter size combination. Plus since I'm using the Chamonix 45F1 I can use it without any bellows extender which was a pain with my 450 lens which really was too long on this format anyway. Thank you all on this thread for your input.