These valve seats are a "natural" for replicating by 3D printing
technology.  I already have files made up for the internal seats
for Ampico valves and the Wurlitzer valves (blue circle on attached
photo).  I could also print the atmosphere cover (yellow circle).
I have not yet modeled the part, but it is easily done.

John Grant
 
 [ Wurlitzer _internal_valve_seat
 [ http://www.mmdigest.com/Attachments/20/03/12/200312_232823_20200312_191211.jpg