Colin,
I believe they were available in the eighties, but finding one now is going to be like looking for the proverbial "needle in a haystack". You could try contacting SRB Engineering in Luton(tel.01582 572471) to see if they can help.

By Colin Barratt on Sunday, October 13, 2002 - 10:06 pm:

Most of my commercial work is architectural and interior photography. I would like to use my 645 50mm shift lens on a ZE to provide clients with 35mm trannies for slide presentations.
Do the adapters actually exist or are they mythical beings? If not can someone sell me one?