Gillbie - the 2 "boxes" are for the ends of the pipe clamps. I wanted to be able to quickly release the clamps if I need to work on an extra long piece, longer then my bench. The clamps would be in the way. After I did that, I realized what a slick move it was because as you can see in the 4th picture, I removed the clamp and inserted a small bar clamp to secure a board I want to cut of the end of.
Deanr - no, I didn't rout out a groove on the underside of the bamboo flooring. The original door (bench) was thick enough to accommodate the pipe below its' own surface.
I got the T track from Rockler.
And for your last question - which is a good one -in the 5th picture, you can see a block of wood in the table. I fashioned that block of oak onto a single end vise so I can clamp any size piece. I stick a bench dog in the whole,place a piece of wood in front of it, secure a fence in the T track and clamp it down. I'll try to take a picture of that this in the next couple of days. That was a good question and did solve the problem. Thanks for asking!
Just happened to look at the last picture - a small piece if wood is snagged in there.
Its' never hot or cold in New Hampshire... its' always seasonal.