I got the pic from the original. But whatever is at the brass site just has lengths and dimensional info. Nothing opened to show price or how things would fit together.
The aluminum track and channel at MLCS is well- illustrated. But it doesn't appear to be something you can go down to the local Farm and Fleet to get. And there would be some machining involved. With the wood version, a nail can be used on either end of the sliding Tee for very large or very small cut outs. I think Hylton uses something other an a nail but the spike worked for me. A pin with a point end and thread end would have to be part of the assembly for aluminum or brass. So a bit of "sport machining" as well.