"the lens sold with the Cosina-made FM10 and FE10 is a 35-70/3.5-4.8. It is a different lens which is a little slower at the long end"
It's also slower at the wide end - f3.5 vs f3.3, so overall about 1/6 stop slower through the entire zoom range.
I had the AI-S 35-70/3.3-4.5 for a while some years ago. I bought it second hand, the shop had two, one showed focus shift when zooming, the other was better so I bought it. I took some good pictures with it but felt it was never quite as sharp as my AI-S primes so I sold it again.