I wanted to give a short write-up on my 1964 Gibson 175.
As some of you know, I've had close to 12 175s as well as a couple 165s.
I'd had them from almost every era, 1964, 1968, 1971, 1974, 1989(4), 2005, 2012
As time went on, gibson made the build heavier and heavier in an attempt to save money on warranty repairs. They also briefly flirted with 3pc mahogany and 3pc maple necks to avoid warpage. Tops also got thicker and glues were changed. Originally hide and then PVA. I have heard that the modern 175s used epoxy for the plates but I'm not sure.
In 2012, gibson was "caught" using laminated fingerboards so it's possible the 175 from that era also fell victim.
I haven't played a real '57 and only briefly played a '57 reissue so I can't tell you much about them.
This '64 is remarkable in that there is almost no top sinkage. By contrast, when you get up to the '80s 175s, they almost all have significant top sinkage. One of the first things I do when I look at a 175 is look at how many threads are visible above the base. On the late '80s models, you often see 1/4" to 3/8" of threads visible. On my 64, there is less than 1/8. Of course this can vary based on the hight of the base/bridge itself. I'm talking the standard base and bridge, including tuneamatic.
IMO, the '88/'89 guitars were the last era that had a light enough build that you actually got some acoustic resonance when you played electrically. Sadly, the 88/89 guitars also suffer from extreme top sinkage. I've heard that Gibson flirted with kerfed bracing but I cannot confirm which eras had this.
My 64 has a couple screw holes in the top which apparently were from a bigsby. It also has replaced pickups (patent # pickups). Tuners, tailpiece are also replaced. It weighs slightly more than 6lb compared to the 7.5lb of the 2012 I recently sold.
Earlier ones have a much more resonant vibe to them than the modern ones. Each decade generally brought heavier builds and had different characteristics, progressively worse build quality/younger woods and subsceptibility to top sinkage, warping, etc.
Will write more later and accompany with a sound demo.