I am reminded that Overland used to offer the parts for the RR-27 group
that had the diagonal fitting described in an earlier posting, and
applied to the last of the RR-30 group. I purchased a package after
seeing a model Keith Jordan built of a 27. These would be fairly easy
to cobble up out of styrene. They are illustrated on two different 30's
on page 215 of the SFRD reefer book.