This high-quality lens assembly was for some industrial application; but I don’t know what it was. I tried it as a finder (using a 10mm Plossl eyepiece; ~23x ) and the image looked good.
I have finally come to peace with myself that I’m not going to use it – maybe you have a project in mind? I’m offering this as hobby / project lens as I have not evaluated it beyond the finder experiment.
This lens is in excellent condition, no scratches on the glass, it is coated and mounted in an aluminum cell. The lens is marked: 9” f4.5 Plumber Precision Optics IBM – P/N 4593053
The lens elements are ~76mm in diameter, the aluminum cell is ~3.65 inch in diameter and ~4.15 inch in length. It weighs ~4 lbs. The ruler next to the lens is 6 inches long.
I am asking $30 for this lens (NOTE: this is for one lens assembly) - buyer pays actual shipping (your choice)