I see that there Majestic tripod heads that are screwmounted - I have a couple of older ones that are post mounted (meaning that they have a hollow tube intended to fit over a tripod post, rather than being screwed onto the tripod) - is there a way to convert a post-mounted Majestic head into a screw mounted one? I want to put it on a Zone VI set of legs.

Also, were there different sizes of post-mounted tripods? The hollow tube of one of my Majestic heads seems slightly smaller than the other, and so the heads are not interchangeable.