Where to unscrew rear of Portrait Unar Lens?

[rossn4]

Hi, I have a Portrait Unar 14 3/4" lens that has some debris inside and I'm trying to unscrew the rear of the lens to clean it out. I am unsure where the rear unscrews. I am including a picture of a similar lens to the one I have. If anyone knows, could they point out the section which I should try and turn. Thank you.

[andrel23]

Hi have you got an answer anywhere else?
I have one

[Steven Tribe]

Is this the recent ebay offering? I was near the BIN button many times!

It should clean up very well, but I can't help you - there are number of people here who have (and use) this totally US/ B&L invention.

The previous thread from 2009 (see bottom of this page) might be of help!

[goamules]

I'd say that after 9 months, he probably got an answer.