Hi.
I dont like so much the skimmed hubs.
I prefer the flanged one, but is very difficult to find the 1963 front “interim” hub.
On my P11A i have the flanged one (i know that someone can say that they are for 750 Ranger only!).
But, if you see pictures, you will find that most of the P11, P11A, P11A Ranger, mount skimmed and flanged.
Maybe they mounted what they found first on the chain?.
Piero