I prefer to try to use the decals in these old kits if I can, even if they're a bit yellow and brittle. I put the sheet on the windowsill in the sun for a few hours to remove some of the yellowness first.
SO I sprayed the model with Future Floor Wax in preparation for decals, but forgot to paint the anti-glare panels. The acrylic olive drab reacted to the floor wax and crackled. I'm calling it "weathering".