Stainless Mount And Block Centerboard Wire?

Description

Never used, but I am not sure what it is. I bought the inventory of a small boat builder a few years back and still haven't figured out what this part is for. My best guess is that it was mounted forward under the bow of a sailboat for a wire purchase to lift the centerboard.
Here are some dimensions that I measured:
sheave diameter 1"
will accept wire/line up to 3/8"
Mounting surface (3 drilled holes) 2 1/8" x 1 3/4"
holes are 3/16"
weight is 8 ozs
Note that leg with the sheave extends slightly beyond the plane of mounting plate. So it seems that it would need to be mounted so that sheave arm extends beyond an edge or some type of base/shim would be needed if surface was flat.
Hope someone can use it!