In the fully depressed position the clutch fork hits the housing and the bearing still has another 1inch to clear. The tabs are still in grove.
Thanks for the memory refresh of your pics, D'man.
You've nearly got it.
Consider the geometry and how the fork and bearing carrier move relative to each other.
As the fork swings forward, the fork fingers rise perpendicular to the bearing carrier. At some point they must come out of their groove.
It isn't clear to me where the fork is hitting the housing, but yeah . . I'd buzz some alloy off with a Dremel or similar.
A couple of other things to be aware of.
The fork fingers wear in operation and form flats and consequently, ridges at each edge of those flats. They can hang up a little.
The groove the fork rides in is fairly snug, so some lubrication will help with the "feel" of how it's going.
Similarly, releasing the large spring on the external lever will help with the "feel", though I don't recall the need to do that.