[Boatanchors] Hammarlund HQ 120X replacement main tuning dial and serial #assignment

[John King]

 I have Hammarlund HQ 120X serial number 7742. Does anyone know if 
Hammarlund had a particular system for assigning serial to 
receivers.Does anyone have an idea what the date of manufacture of # 
7742 might be? 

I also am looking for a fairly straight main 
tuning dial for the HX 120X. My circular main tuning dial is warped and I
 would like to find a replacement. I don.t know if it is exactly the 
same as the HQ 129X or not?

Your input will be greatly appreciated. 73, John, K5PGW