Is this the difference you're referring to?
You're looking for the plastic piece which serves as the indicator pointer...the one that slips into the slot on the shift collar (pictured on the right)?
AFAIK all the replacement collars (and they're the same from '65 up through '77) have the slot for the slide-in shift indicator. If you want one of the style pictured at the left, you'll have to get one from a different column. I've been wracking my brain right now (but it's been a LONG day) and I can't remember what the cutoff point for the two styles is, but I believe it's '65-'70 vs. '71-'77...though I could be wrong. Therefore, I don't know what to think about your '72 having the cast-in style vs. the slide-in style.

It shouldn't have come that way from the factory, though I've heard of stranger things than that.
I just checked the LMC catalog and they show what appears to be replacement collars with the cast-in indicators, but AFAIK they all look like this:
I guess what I'm trying to say is...I'm not sure.

I've never seen those pointers in any aftermarket catalog from the major Ford truck parts vendors. However, I'd imagine it wouldn't be too hard to find one.