Thanks for the compliments I think it's coming out better than I expected.
Sorry, I should have added it to my original post. The roof clamps are "Quick-and-Easy" brand made by a company called Quick and Easy products I believe. I bought mine online, $70 for the set of 4 from NRS (
www.nrsweb.com). They sell outdoor gear/stuff (I have no affiliation with them BTW) but if you search the web there are other vendors who sell them. I don't think they are rare pieces but it took a while to find them, the hard part is what term to search for, roof rack mount, roof clamp, roof rack foot?? You get the idea. You mostly get industrial racks and Yakima stuff for results.
The clamps are nice pieces, cast aluminum, hardware is rubber coated where it clamps to the drip rail. You guys are correct the mechanism is a simple rotating cam lock you can adjust. I had been playing with my own clamp design but this was way easier.
I've tested some different color stains but I'm leaning towards a natural color, it seems to go well with the truck color. Also bought some spar urethane in a satin finish to protect the wood from UV and water.
The rail parts should be here first of the week so I will post some pic's as soon as I get them.
Thanks- Dave