Hi Charaina,
This might become a bit of a wild goose chase...
I have found no trace of James Ambuehl, but he co-edited the edition with Ron Shiflet
( As I got from here; [
www.locusmag.com] )
You
[
www.isfdb.org]
Otherwise, you might want to try the other co-editor and cover artist MINNIS, MIKE; [i.e., Michael Minnis]
I think this is the same as this Michael Minnis (as he wrote several other Smith related publications)
[
www.amazon.nl]
His current publisher; Alfred Bekker / Cassiopeia Press. You can contact him here; Postmaster [at] AlfredBekker [dot] de Yes, its in Germany.
I think there little chance you can still buy an original copy, but they might be able to republish a pod or e-book edition,
Good luck
Frank