There should be one. This thread shows the location of a Mercury VIN, yours might be the same. https://www.jalopyjournal.com/forum/threads/1949-mercury-vin-locations.1062106/
According to my 18th edition of Motors Auto Repair manual, 49 Lincolns had the serial number on the dash panel and the motor number should match. 1951-5 had the serial number on the a pillar.
There should be a SERIAL NUMBER somewhere on it... Never mind the "Purists" who DEMAND that you CAN'T call it a "Vin Number" because a VN requires 17 digits..... Everybody else knows what you mean, ever if it confuses them... LOL!!