On a sad note, I was checking out some of the other frames I need to add covers to, and it seems that my frame #2 is a little out of shape. About 7 mm too wide at the horizontal centerline. I know these things change a little with time, but that's just too much. I checked my frame #2 mold and it reminded me that it broke after I glued the halves and before I scarfed the two halves together. It must have been misshapen when I glued the halves together. I immediately checked all my other frames and they are mostly fine, within 1-2 mm of the exact measurements. It looks like I'll have to do frame #2 over again, but I may have to do others over when I get closer to assembly due to unforeseen nuances. Maybe, maybe not, but after doing it once, I'll have more confidence the second time. We'll see how it turns out.