Nyloc nuts are an excellent idea but because of the drag on the nut as it turns it is a two person job.
I usually work alone on my 1977 13-foot Scamp. I could put nylocs on the closet screws by reaching in the door and through the jalousie window with the screen removed. The the overhead and kitchen cabinet would be impossible to reach both sides. I used an alternative way to lock the acorn nuts on the stainless steel 10-24 screws.
The first picture shows a jam nut which I can get started on the screw first by holding the screw threads above the nut with needle nose pliers. When enough threads are exposed at the bottom of the screw I hold it there with the needle nose pliers. I don't squeeze them very tight. Just enough to keep the screw from turning.
I run the jam nut up tight against the washer. I don't want to get it too tight so as to put excess stress on the fiberglass. I use a thin 3/8-inch wrench from an old Dremel moto tool to hold the jam nut while I tighten the acorn nut against it.
I started replacing rivets last summer and after one trip realized that the jam nuts were needed. I must have given the impression at the Spring NOG that the nuts were always coming loose but they don't.
I don't think Scamp was using snap caps on the rivets back in 1977. A previous owner had simply glued the caps on with silicone or vinyl caulk. They were very ugly!!! The second picture shows how UV damage had reduced most of them to dust.
I also wanted to wet sand the very heavy oxidation off the top of the body and didn't want to deal with the rivets.
I'm not sure if I will keep the screws. I see the advantage of rivets the way they expand to fill the holes, stay tight and break under stress although all the rivets appear to be the original 35 year old rivets in my trailer.
The nice thing about screws is that I can easily take them out and put them back in. I am going to repaint my cabinets inside and out with of all things, paint
designed for fiberglass. Probably Interlux Brightside. It will give me a chance to practice before I paint
the body. My gel coat is getting very thin. The snap caps will have to come back off for that.
I didn't put any sealer on the cupped washers when I put them in so they leak a little when it rains. I cover the Scamp most of the time with the deluxe cover sold on eBay. It keeps the water out and it stays nice and clean until the next time I go camping.
I was hoping the caps would be ok with out sealer. Since I started replacing the rivets I have learned that a little dab of caulk is advised. I will use ProFlex RV sealer as I keep reading how silicone is a no no.
Since I am in the tinker/mock-up/learnging stage on my Scamp the screws will stay for now. Or rather, go in and out until I get everything the way I want it. I might even glass the cabinets in and plug the holes. Time will tell.
The most important thing is that I'm able to go camping in between working on the Scamp. The last picture was taken at the Spring NOG with Carol's 16-foot Scamp in the backround.