Looking for front and back seats for a 54 Eldorado
Hi, if worse comes to worse, the seats from a 1955/1956 Cadillac should bolt up as they are the same body. The fronts should work from a Coupe or Coupe de Ville. You might have to do some alteration, but depending on how far you're going to "go" with the car, you might wish to consider the above. (As the exact seats from a 1954 Eldo are going to be rather scarce on the ground.)
If the car is missing the seats, it sounds as if you've got a long, long way to go, unless someone took the seats out and replaced them with a more modern seat. If your search is fruitless, you can also consider seats from 1954,1955, and 1956 Buick Super/Roadmaster and the same years for the Olds 98 coupes and convertibles.
Best of luck. You also might consider using the on line Directory and contact other owners for possible help.