I ventured out into the cold and ice last night to the local Lowe's store and wandered about looking for solutions. I wound up using 3/4" birch plywood, handily cut into a 2x4 panel and a piece of "markerboard wainscotting" it is masonite with a dry erase coating on it. The whole set up is a bit thicker than the original particle board but it doesn't appear to interfere with the belt.
I set out to check out a piece of post form countertop that was on clearance per the website. 6' piece for $11, but I couldn't find the one piece they were supposed to have in stock. I would have been able to get enough width out of the post form stuff, but I think I would have needed to reinforce it on the bottom. Based on my experience with the original particle board base I don't think it would have lasted for the life of the other components. I have it back together now, with the exception of the trim pieces. The total cost of the project was $40. I used contact cement to glue the masonite panel to the plywood.
I'm not familiar with textured Arborite. I would think anything with much of a texture on it would cause premature wear on the walking/running belt. After I posted I see that Arborite is another name for laminate. Two main brands here are Wilsonart and Formica.
Last edited by Sparky617; 01-09-2017 at 07:33 AM.