108 mm

Fixed the holes in the skirt today. Finally got my hands on a slightly larger than 4" hole saw.
A 108mm one did nicely.

They fit!!

 After that, I gave the panels a couple coats of grey primer, a quick sanding, and a coat of silver.

 Next I'll glue in the hemispheres and attach the panels to the skirt frame, and the bottom part om y my Dalek will pretty much be done!