On the driver door pillar between the hinges, will be a plate with the serial#, made up of year 51, then model 1 for Special, or 2 for Deluxe, so for 2 door Specials it would be 511 and Deluxes 512
Specials didn't come with overdrive even as an option (possibly some exceptions, but as a general rule....). Overdrive was available on Deluxes, and a lot of them had it. If it exists, I'm not getting this bit about the gas pedal (
?) What is that about?? There should be a pull out handle with OD on it below the dash, on the left. IN, its IN "overdrive ready" state, pulled OUT, its locked OUT of overdrive (hence, lockout) The working bits are in the engine bay, and there would be an extension to the bellcrank so that when you floor the gas pedal, an outrigger depresses a switch which has some wiring going to various parts (distributor, transmission etc--all these Borg Warner overdrives are essentially the same) and this switch controls the kickdown to direct from overdrive in second and third.
Under the hood up on the cowl is a separate larger tag, the body tag. It would start 51NN- either 511N or 512N, and that "N" is a number, and for Special it could be 5110-, 5113- or 5114- (utility, business coupe and sedan), and Deluxes could be 5120-, 5124- or 5127- (utility, sedan, coupe).
but there would be another number that would be the actual body number when it was created and welded up waiting to be used.
Here is the link to the registry:
http://www.eskimo.com/~hhagen/reg/reg.htmsee if your car is there already; if not, send an email and add all the info.
post all the info on the body tag here and we can decode it for you, as the car was built. ie where assembled, colour, option groups, transmission that came with it, trim etc. PNT: Paint Code
TRIM: Trim Code
DR: Delivery region (1 for US, 2 for export)
TR: Transmission code
AG: Accessory Group
SCH: SCHED(ule) Number
ITEM: Item Number
ADDL INFO: