Not sure about a 54 but some earlier years you will find vendors with "original Cork" and also solid rubber.
I used a solid rubber on my 37 for a while but it would never "seat" or "seal" tight on the hard rubber and I usually had a leak.
I changed to the cork seal and used 3m adhesive and have not had a problem in years! Just my experience.


1937 Chevy Pickup
In the Gallery
1952 Chevy Panel
In the Gallery
More photos
1950 Chevy Coupe
Pictures!

I'd rather walk and carry a Chevy hub cap than ride in a Ferd.
I can explain it to you, but I can't understand it for you smile