A wheel problem

I have a PIK20. The main tire was in need of a change, so I took the
wheel off today, took out the three bolts that hold the wheel halves
together, then spent over 2 hours trying to get the wheel halves to
separate.

I am stumped. Light tapping has proves that one wheel half will
rotate independently of the other, so that seem to rule out being
corroded together, but the two still won't come apart.

It is a pre-production PIK, serial number 2 and there weren't any
markings on the wheel that I could see to tell what kind it is.

Does anybody have any thoughts?

TJ Johnson