craftgrrl | Help please! - Metallic paints & Acryllic

Very nervous first poster here - I've offered advice before (I tend to crochet like mad) and I've lurked for ages, but this is my very first post.

I'm trying to replicate a part of a mirror frame that long ago, was painted with some sort of gold paint and then with I think are acrylic paints. But it was hung in a bathroom for years and now it's developed rust spots and several nasty if small cracks. I've got no idea what the original gold paint was.

My question is - how does Rustoleum indoor/outdoor metallic paint work with acrylics painted on top? Would a Rustoleum sealant work fine coated over said acrylics? Or would another one be even better? Has anybody experimented with this combo before? At this point I've already hit a snag with the material I'm painting soaking up the paint like a sponge, and I'm getting worried about the deadline (thanksgiving). Any advice would be greatly appreciated!

Edit: Just realized I should elaborate a little more on what this mirror looks like. Not only is the base paint this metallic gold that's gone rusty, the original artist had painted beautiful butterflies, branches, bamboo stalks, and a lattice pattern on this mirror frame. And now everything's got rust spots rising up through the paint and discoloring things.