The 1954 MERC CHASSIS MANUAL calls for either of two seals and does not indicate exactly which is which.
Do you want the seals when you pull the drums or can you wait? The seal will have an INDUSTRY PN on it and will be able to be crossed. Is there a BEARING SPECIALTY SHOP in your area? Better chance of getting a better quality seal than from a box store.
I pulled off the LF drum yesterday. Someone has put alot of new pats in this car. But the seals they installed do not look right. The Chassis manual says the seal part number is 1190. But so far no luck. I have to clean and paint the drums, so time is not an issue. I'm going to measure the ID of the drum and go from there. The bearings have some kind of cheap thin grease on them.
Below is the application chart from the 1954-55 MERC CHASSIS CATALOG -
See if it shows large enough to read. It only gives sizing on one seal, so you will most likely have to go with the ID NO off the old seal, if it is correct.
Where I would try and source brngs/seals is a vendor such as -
PRECISION SEALS seems to be a quality product. If off-shore, the quality may be excellent, depending on the manufacturer. It is just too difficult to operate a manufacturing company here as the government will regulate and tax them to death