I have two nice 150mm f4.5 enlarging lenses for 4X5 negatives. Lenses are both M39 thread mount. Neither have a retaining ring but they can be had for $8 from Calumet Photo.
Both lenses have a few marks in the coating on the front element but not enough to cause any degradation of image quality and since you won't be shooting into the sun; no loss of contrast either.
I put one of the lenses on my Beseler 45 MXT enlarger with a 4X5 negative and it produced a very sharp image at f4.5, very bright as well. Lenses have a white aperture scale but it is not luminescent.
Asking price is $20 Each Shipped in CONUS by USPS First Class
Payment by PayPal, preferably as a "gift" so I do not incur fees.
Please PM with any questions. I am open to trades for these lenses as well - I don't have anything I currently "need" but who knows...you may know what I want and it is sitting in a drawer collecting dust! LOL