Hello David,
I wish you the best of luck in finding one. I posted the exact same WTB and got no response, except JimH laughing hysterically at the near impossible nature of acquiring one secondhand. Eventually after months of searching I found one, but alas not for sale. Be particularly attentive on whether your needs require a cammed or camless reflector, they all had the cam follower (forbdding use with MagHID for example) but some have been removed.