Hi guys, thanks for the responses.  I asked CPR, but no plans.  Asked Mayfair, no go.  These backglasses seem as rare as anything.

Now for the question.  I have heard vaguely somewhere in the past that there may be a method of creating a pseudo BG from a scan, but being a newbie in this area, I would have no idea of the what and how.  Any comments here?  Thanks.