Your scope will be limited to 1949 and 1950.
If you should find N.O.S. fenders, the left GM number is 3690631. Right GM number is 3690632.
Fender Stampings of the '49 and '50 differ from '51 and '52.
Stainless trim is NOT a consideration in varied fender part numbers between '49 / '50, vs '51 / '52.
Keep in mind, the actual vehicle MODEL determined if the vehicle had fender stainless trim ....... or not.
Fleetline and Styleline SPECIALS had no stainless trim on front fenders.
Fleetline and Styleline DELUXE had stainless trim on front fenders.