Bill, thx for the rockler address. I had looked at a couple of sites including Rockler, Woodpeckers and others, but somehow missed that one. That is really almost exactly what I am looking for, I think.
Birchwood, Sorry, but there are no Menard's here where I live in Arizona, at least that I know of. One of the reasons I wanted to do it myself was for the economics, I thought. Then I started looking at and pricing the different blank pieces of plastic and had just about decided to buy an insert, but now with the rockler site that Bill has linked me to, I may rethink about what I want to do.
thx both of you for your answers,