The next problem I encountered was that the dome was seriously out of round (>1 1/2"). This would mean that the brush seal, which I had purchased from Explora-Dome, would not work if installed as instructed - mounted on the edge of the retaining ring facing inward so that the brush contacts the "collar" of the roof panels. I discussed this with Dan at E-D and he suggested two possible solutions: 1) force the skirt of the dome round and bolt it to the wheel ring, but he warned me to bolt only where the dome was in natural contact with the ring or the dome would warp the ring, OR 2) measure the gap between the dome skirt and the collar of the roof all the way around and vary the mounting extension of the brush seal accordingly. I decided to go with the first option. After further examining the gap between the dome and the wheel ring I found that they were only touching in three locations (no surprise there) and two of the locations were very close together with the third on the opposite side. I did not think that it would be possible to force the dome round using just those three locations. Therefore, I carefully measured the gap between dome and wheel ring at four orthogonal points: front (center of shutter opening), back and both sides, and fashioned, by trial and error, wood shims to fit in the gaps at those points. I then marked the location for each shim on the dome and the wheel ring, and we removed the dome and ring from the building. With the dome up-side-down we placed the ring in the dome, used orthogonal ratchet straps to force the dome round, and centered the wheel ring. We then drilled 3/8" holes through dome and ring, front, back and both sides, and then placed the shims and bolted the wheel ring and dome together.
It had also been noted that the collar itself was not round. The collar is in loose contact with the support ring opposite the corners, but there is a very significant gap where the roof panels overlap. While the dome was off, we used Great Stuff foam sealant to seal the gap between the support ring and the roof collar.
After replacing the dome and wheel ring on the support ring we found it necessary to loosen the bolts and adjust the shims slightly to get the wheel ring to ride evenly on all rollers. We then used Great Stuff to fill the gaps between the dome and the wheel ring all the way around.
After all this we found that the dome skirt was not perfectly round but much closer (<1/2").