Only two lenses in the arsenal fail to be recognized as a Rokkor lens. However, these two do carry some unique characteristics that stand out among the rest. Perhaps that’s the reason they were added in the first place.
Soligor 35-70mm MC f/2.5-3.5
Since this is an MC lens, my guess is that this is the oldest. MC (Meter Coupled) preceded the MD (Minimum Diaphragm). This could be anywhere from 1966 to 1977. I actually use this lens a lot, the 35-70mm range is perfect for around town style shooting, and fairly compact for a zoom lens to not hate walking around with it. Not only that, it has a macro ring, for some real up-close pics.
Cosina 70-210mm MC f/2.8-3.8
Where the Soligor stops, Cosina starts. Also an MC , so also older. This is the same focal range as the Rokkor MD Zoom, but this boasts a faster f-stop. Another lens that gets little love, I haven’t used it at all. In fact, I didn’t realize I had it for the longest time. The other lenses were stored in a flight container surrounded by foam, but this lens was left all by itself in a camera bag full of flashes. But seeing how open the aperture is for the range, I’ll have to give it some shots.