A very good question! I’ve created a new page with serial number information so you can sort out how old your instrument actually is. I’ll continue to work on the formatting until it looks a bit neater. But for now, the permalink is here: https://anamazingmachine.wordpress.com/how-old-is-my-piano/
Actually, they can! Well–sort of.
Whenever I do a restoration, or even a simple tuning, I’m always intrigued to see what may turn up hidden within the depths of the innards of each piano. Every little fragment, no matter how small, gives another clue to the story surrounding the instrument.
I was extraordinarily fortunate to recover a great deal of interesting artifacts from the 1924 Haines Brothers’ that I recently restored. The main article featuring the process of restoration can be found here, just in case you missed it: https://anamazingmachine.wordpress.com/2013/02/11/an-even-more-amazing-machine-the-great-player-piano-restoration/
And now a showcasing of the interesting bits found within the dust and muck that was the inner keybed:
What are these things worth? Not much. What do they tell us about the piano? We can infer from these items a great many things, with a bit of imagination. Judging from the Colorado Sales Tax token, we can infer that this piano has been in Colorado since at least the 1940’s –which makes sense, seeing as how it’s the same place from which I found the piano. It also told me (thankfully) that the piano has likely never been completely opened during its life, apart from normal tunings, since none of this stuff was found or removed. As for the rest: we can only guess…