How Did The Halloween 4 Masks Get to Set?

How many masks were on set? Where did they come from? At what point do those masks show up in the film?
Those are questions all H4 fans have asked themselves at one point and those are what we'll attempt to answer today!

Running theories on how the masks got to set:

1. Backup Mask from H2 was on set (School House Mask), Ken Horn made 6 copies recast from it.
"Don Post of Don Post Studios has stated numerous times that the studio did not make any masks for Halloween 4. Period, end of story. Also, I might add, by 1988...the Kirk master and mold were LONG gone."- Billy Kirkus
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Most use the following Gorezone magazine quote taken on the set of H4 as evidence supporting Ken making the masks, not DPS:
"We did not have time to go into the lab and make one...Fortunately, the company had one of the masks from Halloween II. I was able to make some adjustments on it and a handful of rubber backups to fit the actor playing Michael."- Ken Horn

Why would Ken state that he didn’t have time to make extras, then immediately after state that he made 6 extras? In my opinion, he wouldn’t, which leads me to believe that the next theory is the truth and that Ken did NOT create the masks by recasting the on set back-up H2.

2. Backup Mask from H2 was on set (School House/Kelly Meeker Mask), Don Post Studios sent 6 extras to set.

This theory is another popular one, and personally, this is how I believe the masks got to set.
A testimony given by Ken later on in several interviews is that Don Post Studios sent him a box of 6 masks that were all painted “pink with white hair”, and he then modified them (and the backup H2) to be white with brown hair.

Ken Horn stated: "I asked Don Post when they redid it for us to use the Shatner mold and actually use William Shatner cause we wanted the actual true face. I didn't get a chance to see those masks until we actually got on set. I opened the box and there were 6 of them, and they were pink with white hair. I was going, this is not right, they're supposed to be white with brown hair, and I told the producer that it should be changed."
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However, when asked about this Don Post denied it:
"Don Post of Don Post Studios has stated numerous times that the studio did not make any masks for Halloween 4."- Billy Kirkus

When looking at all the evidence combined, it becomes clear to me that the H4 masks were made outside of set either in pre-production or early filming stages.