I have a customer who just got a mint condition Rodenstock Beseler APO HD 240mm f/9 enlarging lens from me. I received the following message:

I received the Beseler 240mm lens today.

It seems to be in excellent shape, but I cannot seem to get any kind of focus with it.
The lens is being used in a Beseler 45 MX enlarger.
My goal is to produce very, very small prints, and no matter how I configure the enlarger head, I cannot achieve focus.

Can anyone help me figure out what’s going on?

Thanks!