Front fork differences in sandcast and diecast K0

[toycollector10]

I have these two sets. The stepped ones are off the November 1969 diecast I am restoring and I will be polishing them for installation. I've seen on this forum that all sandcast bikes have stepped.
The tapered ones shown take sandcast guards. They also take 1969 and probably 1970 diecast guards so at what point did Honda transition to tapered? I believe that K1 forks are completely different.
I will be selling the tapered ones as "fits 1969 and 1970 Honda CB750"....
Also, I believe there is a third type which are  similar to the tapered but they have a shorter taper so they are a cross between the two. I would be interesting if someone posted up a picture of that variation for reference purposes.

[kp]

The stepped pair or obviously K0. That numbers 1 and 3 from the left. The other 2 could be K1s which also had the same mudguard mountings as the K0 They could also be K0 early types as some had a more smoother step
Easiest way to tell for sure is check the seals The K0 have the smaller CB450 type seals which weren't carried through to the K1/2. They're larger