So, a couple of things happened.
Returning to the boat a day or two later, and the front visor’s extrusions had come undone from the top of the windshield. Playing with this a bit, I reiterated my thoughts on it simply being a bit too tight, but also it’s likely not so bad that adding a few snaps into the front visor wouldn’t solve. Of course, while Great Lakes included the screw base/socket portion of the snaps along with the canvas, they include 3/8” snap sockets/screws which aren’t quite long enough for drilling into the extrusion channel.
Meanwhile, the original install instructions came through, which was a bit interesting - it wasn’t full instructions or anything so helpful, but it did have some dimensions worth noting.
Measuring the frame bracket locations several times has me stumped. Initially I thought my measurements were off, at least for the bimini frame, the rear camper was spot on. Measuring again and everything seems to be on the money, although there’s some question as to if the measurements supplied are straight horizontal level measurements (e.g. up the angled side windshield or level along the bottom, then extended upwards), but even there the differences would remain - pretty damned small.
I had been leaving the camper top (mostly) in place, then we had a storm ...
I had only put a handful of the side snaps in place, understanding I migth be changing the geometry of the frame if I had no other recourse, so I had intentionally left the rear canvas unmolested. Even so, everything was tight ‘enough’ that I’d come back to see the front visor had popped out of the windshield extrusions some days. We had a mild storm, and basically - it just wasn’t close enough, as it sat, to really leave in place - so for the time being I’ve removed the camper, front visor and sides.
What next?
Well - I don’t know, honestly. Cove Marine has been good and willing to try to go back and forth with Great Lakes, expecting them to ask for additional measurements to see if we can sort where things are off.
It’s close enough in general that it may be a case of stacked tolerances, a bit off here, a bit off there, just getting it to the point where it just won’t go together without real risk of tearing or excess stress.
I may try once more to work on the windshield, but more than just the center section. Looking at where the side glass and the front glass sections meet, it’s not fully flat - but I’d likely need to do some re-drilling to make this happen. I’d effectively remove all screws between the side and front glass frames, and effectively pull the entire shield upwards and back slightly, then possibly need to re-drill a few holes to lock everything back together. I’m not convinced this is the answer, but as the whole frame set and canvas behavior effectively ‘rocks’ back and forth on the frame, being limited by both the front (attachment to windshield) and rear (attempting to attach in the rear) - it reasons that if I’m able to lift the windshield a relatively small amount, it can only improve things at the rear of the frame.
Beyond that, I may well wind up having to shorten the rear frame slightly, but I’ll only resort to that in the event I am 100% satisfied with the way the front visor and sides sit on the front bimini frame.