Remember the Zone VI Aristo Cold Light head for your Besler 23CII? I wish I had gotten one while they were still around but like most things I could say "I wish..." to, you think all things currently available at the time will be a round ten years from now. I would have liked to try it out as opposed to the condenser head but I reckon they're history now. I don't know if anyone makes those these days. I'd almost be tempted to break out my mothballed enlarger to try it if they were still available.
I know you can probably find them used on eBay but no telling how much usage they've had.
I know you can probably find them used on eBay but no telling how much usage they've had.

