so I think you forgot a couple of things.
What shaft did you use?
Where did you get the collar?

Did you have to open up the inside of the ford wheel? or let it go?

Why did you decide not to use the mopar wheel chopped up a little?

Do the sensors provide the same output?

Just wondering.

As for pining the collar, it looks like there is a gap to tighten it to the shaft? But yes I think a pin would be better.

The housing for my mag does not have any slots or holes. only a notch for the sensor wiring to come out.

As for lining up number 1 cylinder, I think it actually matters more the relation to the rotor to that number 1 slot.
So where it point to in the ford vs where it points to in the mopar.
Since it would be adjustible based on that relationship not where 1 is.