Idahonancy, I love your teeter totter! And your beautiful goat (Oberhasli, I beleive) looks just like my two Obie boys (Moose and Apache). Here they are:
Skippy looks like he is having a ball. Thats a great video. My tallest goat gets under one end of the teeter totter, hunches up his back, picks it up and moves it around. He walks in circles as the oposite end is stuck in the dirt. It is a fun toy to play on with the goats. They out weigh me but leverage is everything.
That halter maybe from Jeffer's Animal Supply or Hoggers. It is goat specific. I only use rope halters now. Rex has them at Northwest Packgoat Supply, lighter weight with better control and fit.
The hinge on the teeter totter is a short piece of pipe. Pipe tie downs that you use to hold a pipe onto wood are holding it to the 2 x 8. I put end caps on the threaded ends of the pipe. The pipe sits on the 4x4 legs and is block in place by wood. Not to tricky, its not really a hinge, it is a pipe sitting on wood. I just made it so it could not fall off.