'failing-era' organ console tags

When I showed my collection of assorted old pipe organ console tags a few days ago, I mentioned that they ranged in age from the 1930's-1990's, which remains the case. I also mention that they're made of whatever sorts of plastics were commonly in use at their time.

https://www.collectorsweekly.com/stories/305064-my-collection-of-organ-console-tags

What I *didn't* mention about that assortment, however, was that it is highly likely that *none* of those were products of roughly a decade's worth of time in about the 1940's -- THESE fit that era/time frame however, and happen to exhibit exactly WHY so *very few* of any at all from then actually survive to this modern day.

The larger is an actual "nameplate" that showed the name of an instrument's builder, VERLINDEN ORGAN COMPANY of Milwaukee, a likely small firm I'm not sure I've ever known of. The smaller tags are, as the ones already seen, 'utilitarian' in nature and in this case are all still mounted to a narrow strip of mahogany molding along with colored glass indicator light bezels. I do not believe the two pieces actually came from the same console.

What is *most* obvious with the larger nameplate is that -- for *whatever* reasons -- the specific formula of *the plastic itself* was, while perfectly acceptable at the time, inherently FAULTY in function when given 30 odd years of age -- during which, slowly and gradually for the most part so nobody really noticed, they *ALL* shrunk, cracked, and fell off of whatever they were mounted on. The little ones here have only shrunk out of their original shape, but the nameplate has actually fractured lengthwise thru its thickness in addition to losing corners.

I cannot say I know what precise variety or brand of plastic material it was, but I believe it would have been something existing between 'bakelite' and 'acrylic' on the timeline of commercial plastics. Maybe some of our vintage jewelry experts can speak up with more information in that regard, I'm pretty sure the costume jewelry industries suffered the same ultimate problems with the stuff during the same period of history...?