I don't consider myself an old timer yet, but I have seen a few county fairs in my time. I would say you have an authentic homebrew crystal radio and the January 1923 date inside is entirely plausible. First off, the nickel, brass, and solder have darkened naturally which is a difficult thing to replicate. The parts are absolutely correct for the time frame. And the three pairs of headphone posts are a nice touch. The radio would not be capable of operating a speaker directly so multiple headphones would be used to make it a family experience. Somebody building a replica today might not think that was important, and not want to invest four more binding posts on it.
I would suggest connecting a crystal diode (eg. 1N34A) or modern small signal diode across the detector as a first go-around to get this going. You will also need high impedance headphones and a good antenna and ground as mentioned. If the crystal is still in the holder it will likely be oxidized to the point where it is no longer usable. Galena is a naturally occurring crystal of lead sulfide; when extreme pressure is applied by a point contact, a semiconducting junction can be formed which works as a detector. But this doesn't happen everywhere on the surface of the crystal; you have to hunt around with the cat's whisker to find spots which work effectively. Problem is, after many years of exposure to the atmosphere, galena tends to oxidize and darken, making it harder to get a good contact. You can make new crystals to fit your holder out of fresh galena or iron pyrite; instructions here:
http://oldheadphones.com/crystal/info/mount.htm