Cute little lens
It looks like a short version of the AI 43-86/3.5.
It has some interesting mechanics, when the zoom ring is pushed forwards, the front element moves backwards.
The hood is an HK type with a thumb-screw which slips on over the focus/zoom ring. A very clever design, when the zoom ring is pushed forwards to the 50mm setting, the hood gets deeper, pull the zoom ring back to 28mm, the hood is less deep, so it is always optimally shading the lens regardless of the focal length.
As Ric said, sharpness is good, bokeh is on the harsh side. Shooting into strong light produces ghost images although at certain focal lengths and with careful framing this can be minimized. The older 28-45 also suffers from this like many other early zooms.
The zoom range is small by modern standards but it still covers a useful 28-35-50mm range and the macro mode is handy. It is interesting to compare with the Nikkor-H 28/3.5, the zoom is a little larger but has the same focal length and speed, plus it zooms and focuses closer. Amazing how optical design improved over 20 years.