I saw this Ricoh camera and lens up for auction and though I could not identify the lens from the image, offered an amount I didn't mind possibly wasting for the opportunity to find out what this lens was. I won the auction and it arrived and I shot a few digital images with it.
It turned out to be a constant 3.5 aperture Vivitar 35-105mm zoom with a close focus mechanism. (Well closer than the MFD without it.)
A quick look through the WWW seems to indicate it may have been made by Tokina, though their own 35-105 does not seem to be a constant aperture.
It does not seem to maintain focus point through the focal lengths and at 105mm seems to focus on infinity before reaching it on the lens scale. Is this to be expected?
I like the lens, weighty though it is and would appreciate a forum member providing their insight into it.
The Ricoh camera seems to work well, I have only just run a film through it and will get it processed. Seems a nice camera, though obviously lots of plastic and the handgrip is not comfortable. I'm happy I took a punt.