Very true re: ss#'s and factory changes. But even with all those changes Guild management has, with few exceptions, focused on building good guitars. Musicians and experienced guitar folks had key roles in the company. So they kept the core values of the company on point. Gibson during the Norlin years for example made lots of bad decisions re: bracing, plastic bridges, large bridge plates solely to reduce costs and limit warranty work. In recent years Gibson decided to be a "lifestyle" brand. Again losing the focus on musicians and guitar.
I've found both Gibson & Guild guitars to be what works best for me since the '70s, and have owned many of both brands (as well as a number of Martins along the way). What I care about is a guitar that's satisfying in my hands, based on tone, playability, and other less meaningful considerations like aesthetics. Who's operating these companies has periodically been an unfortunate mess in both cases. But what matters is that on the shop floor, there were workers trying to build the best guitar they could - while being given different parameters at different points in time.
When you look back, I think it's a bit of a stretch to say that Guild has historically had it's guitar-focused act together any more so than Gibson. Guild was sold to Avnet, a corporate entity, in the mid '60s. Did Avnet have good guitar making foremost on it's mind? Of course not. Fender was sold to CBS in the '60s as well. And Gibson was sold to Norlin in '69, with the same basic outcome in all cases. These were not guitar-musician oriented companies. They all had profit as their central focus, and unfortunately for them, the import instrument boom hit at just about the same time. By the mid '70s, they were all (including Martin) sucking wind trying to find their place in a market becoming dominated by good quality Japanese imports. On the acoustic side, the big three were all overbuilding their instruments. All had large rosewood bridgeplates & a beefed up build (the neckblock on my '76 Guild G-37 is big enough to build a tiny-house all on it's own!).
Gibson's plastic bridge? Yes, a stupid idea, but it actually debuted well before the Norlin era in 1962. In fact McCartney's Texan originally had an adjustable plastic bridge. As goofy as it was, this bridge (in it's adjustable version only), created a metallic-overtoned sound that is quite unique & desirable to some (including myself). I currently happen to have one of these on a '66 Epiphone Cortez (Gibson B-25 clone), and it remains in perfect structural condition. I've also owned two others in the past. Anyway, guitars employing this bridge essentially remained the same as earlier models in the remainder their overall build until 1967, when a rosewood bridge returned but beefier build traits began working their way into production (again, pre-Norlin). When Norlin did actually take over in 1970, they initiated wholesale changes that removed the last vestiges of Gibson's historic acoustic platforms, and indeed, attempted to beef up the overall build even further. Meanwhile, Guild's overall build got heavier in the '70s, as did Martin's (to a lesser extent).
By the time the '80s rolled around, both Gibson & Guild were mostly on their deathbeds. It took Henry J. & partners to rescue Gibson & begin what eventually became a very successful turnaround. Unfortunately, Henry got greedy & engaged in company-destructive decision-making that would lead to his eventual downfall. Meanwhile, Guild went through ownership changes including the short-lived Gruhn era, and could never find a strong footing in the marketplace. When Fender took over in '95, I once again had high hopes for the Guild brand. But bean-counter thinking ruled the day, and we saw the ill-fated transitions from Westerly to Corona to Tacoma to New Hartford - along with Fender ending production on USA-made Guild electrics altogether.
By the time Fender had totally given up on Guild and sold it to Cordoba in 2014, Gibson had regained it's footing in the industry, but Henry was about to implode the company, mainly through his numerous industry-related acquisitions that didn't pan out, and his I-know-best, one-man-decision-making style. Ironically, when Henry's management style drove Ren away from Gibson to Guild, it was probably one of the best things that could have happened to Guild in many decades.
Now with Cordoba trying to resurrect Guild acoustics, they had the perfect person on board to build a factory from scratch in Oxnard. Ren had already done it once in Bozeman, and he did it again in California. He didn't stay long, but he put everything in place to give Cordoba a fair shot at giving USA-built Guilds a future. In the meantime, Gibson has now undergone another ownership transition, but continues building both acoustics and electrics in the USA. As always, you need to sift through them to find the best ones, but they are there, and overall they've built a ton of stellar instruments during the last few decades.
My hope of course is that both Guild and Gibson will remain stable companies for the long term. Lord knows, by now they both should have learned enough about what not to do!
