Contact these three vendors to see if they can help you. Joe Hudacek says he has hundreds for sale from 1950 on up. Jim Tucker also has them to sell. All three vendors rebuild your old ones.
Jim Tucker Rebuilder of Harrison and Ranco heater control valves. New valves for sale 1950 -1975
29597 Paso Robles Road
Valley Center, California 92082
760-749-3488
http://www.heatercontrolvalve.com/Joe Hudacek Rebuilder of Ranco and RobertShaw heater valves. New Ranco heater valves for sale
6606 Banks Avenue
Superior, Wisconsin 54880
715-392-6169
Cell: 218-213-8906
http://www.heatervalves.net/Atwater Kent Temp sending units, coils, fuel sending units, tube radios, vacuum advance, voltage regs
12 Jacques Street Worcester, 1920s to 1970s (mostly 30s, 40s, 50s)
MA, 01603
(508)792-9500
http://www.mykmlifestyle.com