Found a fixable 1928 Chrysler Plymouth model Q tourer. The Fedco is illegible, however the engine number is Q180778. Tag office says it can't be registered if Vin# is illegible. Is there anyway to cross reference engine number, find out what fedco number is and have dash emblem refurbished to new condition? Bill of sale only and owner doesn't know fedco or know history of car. I was going to trade another car with owner today, until I went by court house after seeing car and was told it couldn't be registered. I do, however, have an old motorcycle owner might be interested in.
Your 1929 Plymouth model Q is an early production model. The starting engine number for the Q series was Q175001. So the engine in your car, Q180776, was the 5,776th model Q engine built. Not all those engines were installed in Detroit-built Plymouths, though, as the Detroit plant also supplied the Canadian plant in Windsor with engines as well as for the new Fargo Truck model QC Packet.
The only cross-reference I can think of for engine numbers and serial numbers is the build record for the car, but Chrysler Historical has them only back to 1930. However, the FEDCO plate on the instrument panel had the letters/numbers embossed (raised) on the plate, so you should be able to use some sandpaper on a wooden block to gently remove the crud on the raised portions.
The FEDCO numbers for the 1929 Plymouth Q started at HL-950-P in Detroit and went up to HD-999-D, and then from RW-000-P to RH-977-H. The FEDCO letters have numeric equivalents - W-0, P-1, C-2, H-3, R-4, Y-5, S-6, L-7, E-8 and D-9. So HL-950-P is 379501. On the plate you should find two letters, three numbers and then one letter, as above, I believe your plate is vertical.
Around the each letter you would find the letter repeated three times in small letters - HHH. Similarly each number was repeated three times in small numbers - 999, or spelled out three times - NINE NINE NINE. Seven was done as SEVN.
See if that helps bring out the serial number.
Bill
Vancouver, BC