By far the most difficult-to-find item needed for my catboat build is the steering quadrant. Edson has one in it's catalog, a custom cast bronze item costing in excess of two thousand dollars. It consists of a yoke that bolts to the tiller, the quadrant itself, which is a pie-shaped bronze casting with teeth on the radiused rim, and a shaft for the ships wheel with a pinion gear that engages the quadrant teeth.
Lets make one instead.
The radius, measured off the pintle center, will be twenty-four inches.
There will be forty teeth on the edge of the quadrant.
The pinion gear will have ten teeth, giving the wheel four turns from stop to stop.
It's a start...