Need Source for Slip-On Foam Yoke Grips

I've seen slip-on black foam grips that you can use on the skinny mid-60's
Cessna control yokes.

I'm not talking about the leather wrap covers - these are like an open-cell
spongy foam that just slips over the yoke "horns".

I've searched King, Sporty's Aircraft Spruce, the archives, all to no avail.

Anyone have a source?

Thanks;
Carl