cb750 f k2? amount of fork oil

[mackegr8]

Hi. According to the papers of my bike I have a cb750F K2 from 1975. Thats a model I can't find anywhere. I can only find just F or just K2. And them both two models needs a different amount of fork oil. So how do I know the right amount. I believe it's a F since the K2 where made 1972.
Anyone that knows how to figure this out?

thanks //marcus