Anyone care to guess what enlarger this lens board is designed for?

[xkaes]

I'm at a loss. It's 3 1/4" x 2 1/2" with a 3/8" recess. The reason I say recess is because it has a 34mm hole, so it was designed for lenses with a 32.5mm rear thread, and these are usually shorter focal length lenses which often need a short recess.

There's no brand name or number on it, but it does not look home-made.

 

[AnselMortensen]

It looks like it would fit an Omega D5, and possibly others.

 

[xkaes]

That's what I first thought, but Omega lensboards are round. Here's a recessed Omega board: