Thanks Jack. That sounds kind of reasonable. I looked I looked in Petersson's "Rigging Period Ships" at anything that had to do with the spritsail and struck out. None of the drawings showed anything that looks like this saddle with the holes thing. It does look like if it was there it would be handy for looming lines though.
Frank, I couldn't find anything like chestnuts. I found chesstrees but they are completely different. Cleats just brings back to many hits to be much use.
It's gotta have a name, everything on these ships does.
Vada calls it a saddle but I can't seem to match that up with anything.
Oh, Stuglo calls it a "saddle for running rigging"
The False Rail Shaped board-like structure fixed to the curve of the Main Rail Inboard flat, outboard paneled effect.The inner face flush with the Main Rail Lining. Thickness, 2.12 mm with groove recess 0.53 I didn’t feel able to make this recess at a constant depth, so I made a composite of 3...
shipsofscale.com
Sounds like you're right Jack.