Hey bob, I was going to shoot some automotive clear but did not. I shot some Polyurethane clear over the fuse. I did wet sand the fuse just a tad, as if you sand it very much, you will take all the paint off. I used the polyurethane in a spray can. It does tend to leave the color white a off white, but I have the yellow one and it actually made the yellow match the covering a little better.

I would test the area back where the engine goes. I think you will be ok. Just spray it on back there and give it about 15 minutes. I think you will find it will be ok.