'65 Speedo Cable Cover is Metal

My Formula S 904 has an all-metal speedo cable (photo #1). Are the aftermarkets all plastic now? Should I keep using the old one? (speedo on the dash probably doesn't even work right anyway)

If I remove it from the transmission, what kind of seals/gaskets/o-rings will I find inside? I was expecting to see an adjustable speedo gear orientation ring like I have seen on other Mopars, but I don't see any evidence of that (photo #2). Thank you.

speedo cable 1.JPG

speedo cable 2.JPG