I've searched online and this is the only Le Supreme that I've see that has Diamond Knurling on the twist knob.
I'm speculating when I say that it would have been a "time saving" exercise in that only one set of knurling wheels was needed.that it would have been one of the last batch

How does it shave?
Its a mild shaver, even at its most open.
I usually flip the topcap around so it's the "wrong" way around because that evens out the gaps. If I want a bigger gap, I just adjust it.