There is no serial number, although I see no traces of finger board being carved by the original fret. From this, I suspect that it was not a commercially sold product, but the details are not known.
Even though there is no evidence that it was cut of a finger plate in the original fret, there is no serial. It is a possibility that it was not a commercial product, but I do not know more details.
There is no serial number on the fret board, which is original, and no traces of scraping. It may not have been goods on the market, I couldn't research further .