If anyone needs parts for a thomas 337 compressor here is a list of parts and an exploded view of the compressor.
here is the contact info for the parts supplier
contact: katie at fluid systems and components inc
# 816 - 777 - 3868
kdolembo@fluidsystemskc.com
they also sell check valves half of what most minitruckin suppliers sell them for... (ie, cv-series 1/4" check valve for $8.00)