Gibson's design evolutions

[Regalese]

Aside from my very sweet "49" J-45, I have a couple of ladder-braced LG-1 flattops in excellent condition and of 48-50 vintage. One has the tortoise guard, while the more pristine has the less common firestripe like my J-45. The tortoise weighs in at 3lb, 12 oz, the firestripe at 3lb, 10 oz. The most striking design variance is that the tortoiseshell has the standard soundhole placement at 3-1/4" from the bridge while the firestripe has the hole 3" from the bridge. I first thought the FS may have been a transitional piece with the hole placed to make room for a 20-fret fingerboard but with a shorter 19-fret fingerboard installed instead. I searched some old images and found that even some of the banner war-era models had soundhole placement 1/4" closer to bridge with the larger distance between fretboard end and soundhole. Sound hole placement is not supposed to affect tone. Sound holes are both standard 4" diameter. Does anybody know what Gibson's thinking was in placing sound holes on some instruments 1/4" further from the fretboard years prior to the introduction of the 20-fret models? The lighter guitar is, as I'd expect, extraordinarily rich and resonant with great sustain, especially for a straight-braced top. In some ways, it's almost too resonant because, although it's plenty loud, I'm not sure it has the character and sweet balance of highs and lows that the tort has, although the tort sounds slightly choked compared to the lighter guitar. I was once told that there were some LG's built in the late forties that were almost too light. Any luthiers out there know what the tonal downsides to construction that's TOO light are? I'm surprised that straight-braced boxes could be so effected by weight variations. Maybe I just need to try some different strings on it. Hope someone will chime in......... BTW, another unusual feature of the lighter LG-1 is that the top has a very small third piece on the bass-side shoulder just adjacent to the binding and only extending maybe 3/8" beyond it into the very tight-grained top. The guitar's tone makes me wonder if the top had been intended for an LG-2 until it was discovered it wasn't quite big enough. Maybe they didn't want to just throw it out, so they added the extra piece to enlarge it and used it on a cheaper LG-1. I got lucky because the guitar sounds much better than most LG1s.