[
I'm debating using either naval jelly OR Ospho on this backside. I COULD use my El Cheapo Craftsman siphon sandblaster if I stay back so as not to warp it. Opinions?

[/quote]
for what it will cost you in time and materials, plus getting it media blasted and painted you can buy a new chrome one. Just be sure to paint the back side with a sealer coat, as it will rust eventually too.
http://www.ebay.com/itm/1955-1956-55...f0f9a4&vxp=mtr