Hi Mike,
Slightly simpler way to do this although not as cool. I made my base from the a piece of the pre-finished 48" shelving available at the home center. Then just put the angle AL directly on its face. The shelving comes pre-covered with a formica-like substance that is slick enough to use with out making the roller.
Some times the piece on the bottom of the pile doesn't come out great but works well. Also, handy for squaring up formers!