Mast connectors
These are drop-in concrete wall anchors, used to connect the sections of the mast together along with a section of 1/4 x 20 threaded rod. As described in the QRP Quarterly article, Gorilla Glue or other polyurethane cement is used to secure the anchors in the 1/2" O.D. 3/8" I.D. aluminum tube sections. The drop-in anchors are Ace Hardware item number H372080, 1/4" "drop-in anchors for solid walls (3/8" drill hole size)".
To install the anchors in the end of the mast section, first remove the expander plug...it will push right out. Using a stick or nail, smear the glue inside the mast section to within about 1/4" from the end. Then, wet the anchor with water (important!) and slide it into the end of the tube, slotted end first. Push it in until it is about 1/8" recessed from the end. The water will begin the expansion and setting process of the glue. It will fill the slight void space between the wall of the tube and the anchor and work its way into the slots on the anchor, providing a very secure connection. The glue sets in 24 hours.
Feed point insulators
I have used all three of these at different stages of development of the antenna. The large PVC "tee" connector has the FT-114A-61 2.25:1 broadband matching transformer inside.
The weights of the three are as follows: Large "tee", a hefty 9 ounces; the 3/4" "tee", 4 ounces; and the PAC-12-style insulator, 3 ounces. The toroid could be mounted on the back of the PAC-12-style insulator. A modified 3/4" PVC "tee" can be easily built with bolts and nuts on the back for attachment of base matching capacitors. See Phil Salas' article, "Antenna Base Matching" on his site, AD5X.com.
Homebrew tripod
The little tripod mount (legs not shown) is made from 1/2" PVC, and I believe it is called a corner riser connector. I purchased it from Ace Hardware. Two of the end cap fittings are slip fit, while the third is a screw-in cap. The feed point insulator (or your camera, with a section of treaded rod; the 1/4" threads are the same) screws into the 1", 1/4 x20 coupler nut. The tripod legs are made the same way as the mast sections, with the drop-in anchors.