"...I made was a very straight piece of 1 by 3 I glued and tacked to a piece of quarter-inch plywood. I then cut the plywood to the final size by running my saw down each sides..."

That's basically what mine was, but I made mine out of 3/4" plywood. To make it work slicker (no pun intended), I used some paste wood polish on the surfaces the saw body moves against, that really made a difference...