PG Adapter Ring?

I have a cast iron adapter ring for the power glide transmissions PN #3742366 date code D 3 58 Google says it fits 55-61 passenger cars and Corvettes. Seems in good condition other than needs a trip thru the glass bead machine to remove the rust scale. No obvious damage or broken out mounting holes. Worth keeping with hopes of selling it to someone doing an original restoration? What sort of value might it have? Bead blast, prime and paint (color?) or blast and leave natural finish? Thanks for any input.

Put something on it to prevent future rust.. even if just clear coat... :) (or cast iron gray)
Yes, I think worth keeping as they are thin and do get broken... someone will want it.