A customer brought in a 50s(?) picture with a gold crackle foil mat. The same gold foil is around the frame; topped with plexi. She wants to take out the outdated print and replace it with a mirror. I opened it and sure enough, the gold crackle foil mat which she loves is painted onto the glass. How does a mirror look under glass? How about if I space it away from the glass and painted mat? Will it work? Please help!