I should preface that I know nothing about pianos.
In my area, I have the possibility to purchase a Yamaha No U3 Nippon Gakki for about 1600/1700ā¬
Searching for the serial number, it seems it was built in 1965 in Hamamatsu, Japan, but I haven't been able to find any other information, such as whether it is original or not, etc...
What would the value depend on? Mostly on the current condition/if there are any faults, or also partly on the model and the year?
In my opinion, it depends on what you are looking for and for what purpose. There are beautiful "furniture" pieces and beautiful musical instruments, both with important markets depending on the objectives. If you need an antique piece, the information you seek is important... but perhaps you can find something better from a musical point of view.
Conversely, if you were looking for it to study (at what level?), originality might not necessarily be interesting, etc. ... because the important things for a musical instrument could be others ... such as good mechanics that allow you to study with satisfaction and without "hiccups". The voice of the instrument and other technical details to tackle every repertoire
