ron you have me really scratching my head
I have replaced a bunch of gas valve coils in my day at one point I was keeping up 1400 plus laundry machines out of those they was a good 600 gas dryers, then traveled most of Tn and 1/2 of Ky in commercial laundry equipment for a good 6 years and now in home appliance service for the past 8 years and as I think about it most everything gas I delt with was natural gas, in home service I have replaced gas valve coils on a few dryers that were on propane but thats all I can think of, (as of now anyway) every thing else was on natural gas and that never dawned on me until I saw your post.
home dryers use the same gas valve with only changing a orifice as I know it? and I have replaced coils on those on propane.
it very well could be the gas valves are so small and dinky on campers that only the complete valve can be replaced. I will have to take a closer look at my junker next time I'm up there, I thought the coils I made continuity checks on looked like they would slide right up and off? not to say that I could find a replacement tho? only thinkin that in my mind