What type of glossy preservative is compatible with slickrock silver? I had some regular spray lacquer and krylon preserve it lacquer for printed photo preservation and both turned the slickrock white

Michael,
What is your end goal for coating the slickrock paper? Generally, we don't recommend spraying glossy papers: as you have discovered, the products usually don't interact well with the paper surface.

I am using the paper to construct a large scale model of a b-58. the finish of the paper actually approaches the actual finish of a bare metal aircraft. The project will eventually need to be protected against accidents, and some phases of construction could use protection as I go. Any suggestions?

Sounds like a very interesting project. Unfortunately, I don't have a suggestion for coating the Slickrock paper, as it is not designed for that purpose. The only thing I can think of would be to use plastic wrap to protect from scratches, and wear cotton gloves when handling the paper surface as it is very hydrophilic, and will absorb moisture and oils from your skin. Good luck!