Bausch and Lomb lens identification

[scibod]

I have a lens which has been in my garage for over 30 years - time to go!
I would like to identify it but can get near but not really spot on. I would appreciate your expertise with it.
It's details are Bausch and Lomb anastigmat No 2347989
It has a front lens diameter of about 68mm and a focal length of roughly 55cm.
The aperture stops are f10 11 16 22 32 45
The barrel says Bausch & Lomb Optical Co. Rochester N. Y.
It looks like an f10 process anastigmat in the B & L catalogues but the aperture stops are the wrong values and go the other way.
I am reluctant to throw it out when I don't know it's pedigree! Any thoughts would be much appreciated.

[goamules]

You are close enough in your assumptions, to sell it on ebay. Worth about $20 bucks.

[Jim Noel]

It is definitely a process lens off a process camera, thus the reversed aperture scale.

[scibod]

Thanks folks, much appreciated here in the uk