1950's Reo Gold Comet Truck Serial Number

Can anyone please tell where to find the serial number used for registration purposes on a mid 1950's Reo Cold Comet 1-1/2 or 2 ton truck? Thanks a lot, Bob Woodburn

 

I've only ever seen one ... but I think I read somewhere that it is on the firewall inside the engine bay, but I could be wrong. Look for a plate riveted to the firewall. If not there then maybe the driverside door

 

this is off a 1951 gold comet bus, don't know if it is the same but basicly this is what your looking for hope this helps