On the boat with the pin, the mast steps thru the deck to a keel
mount. Once it is in place, a square wooden (bushing) piece fits into square mounting area built into the deck. Drop it in place, install the pin, attach shrouds, rock forward, attach forestay, tap block into place, tighten forestay. The (tabernacle/foot) has several holes in it making it so that you can adjust the angle of the mast quite a bit more than the rigging
allows. I suspect that the original mast was a rectangular profile wooden mast that fit the hole in the deck without the added block.
The Y-flyer rig goes with this.
I plan on making this the ultimate day play boat for my area. Since I am building it, I was considering abandoning the pivot. Maybe not now!