Hi:  Thanks to all who gave me hope and direction, with particular
thanks to David Beierl.

I inverted the unit for a couple of days then fired it up on 120v.
Volia after 12 hours running in shop the internal temp was down to 36F
(ambient about 75F).
Tomorrow I will switch to propane and see how that works out.

Took the opportunity to install a computer fan in the city water port
as per Frank's advice.

In my research I encountered more than one report of cooling failure
while running propane after the fridge had worked properly for days on
propane up to the cooling failure. The reports mentioned that the user
switched to 120v, reestablished cooling then switched back to propane
and all was well.

Thanks for the help.
Ian