David,

Here are various tailgate chains and covers.

I think the original were zinc/galvanized plate, and I do not know if they came with black rubber covers (I'll look for a factory photo). I use stainless steel chains.

this 1954 illustration shows a cover

a better illustration of a cover in 1954

chain cover on 47/48 pickup (I think there is a chain cover?)

Tim
1954Advance-Design.com
1954 3106 Carryall Suburban
1954 3104 5-window pickup w/Hydra-Matic
The 216 and early 235 engines are not "splash oilers" -- this is a splash oiler.