Beseler 45A Head on Beseler CB-7 Enlarger?

[Grayscale]

I bought a used CB-7 enlarger. It came with the condenser head, but the previous owner recommended the Beseler 45A Enlarger Light Source + Controller instead. So I found one on eBay and bought it. Apparently, you can buy an adapter to use this head on a 23C II enlarger, but I don't see such an adapter for the CB-7. Does anyone have experience with this combination? The previous owner said he used a sweatband around the base of the head to make it fit snugly in the round hole of the enlarger. I guess I can do that, too, but I wonder if there's a more-elegant solution.

Thanks in advance for any help.