I finally got to building new leveling blocks for the motorhome. I opted for low-tech, and built them from lumber.
I used three levels, rather than the four I was originally considering, each 6 inches longer than the other. I also used preserved wood, although it’s a bit more than is needed since my blocks tend to break long before they rot.
I went with three levels each, since the highest number of blocks I’ve needed was three. Also, if I was to need more, I could place a single block under the new ones.
Also, to keep me from rolling off unnecessarily, I added the 6″ pieces I was going to use as the top level on the end as a stop. You should feel hitting these if you go too far.
So, with the cut ends treated, here is the finished product. Next week, I get to find out how well the work…
Doug Rutherford 
Rather than permanently screwing mine together, I drilled holes for 2-3″ carriage bolts in each one, which I can easily install or remove. So I can raise each wheel on my pick-up from 1-1/2 to 4-1/2 inches using one, two or three planks under each wheel, with none under the highest spot. Come take a look.
I thought about that but decided it would be easier to permanently mount them. Since I used screws, it is rather easy to change my mind though.