Kawai have been stamping factory specific sequential serial numbers on their pianos since 1927, they can be found on the frame somewhere normally around the middle. They are between 4 and 8 digits long and may or may not have a letter at the start. If present this letter may denote which country the piano was made.
This tool will decode the serial number of your Kawai piano to show the year and location of manufacture, it works by firstly decoding the factory code to see where it was made and then comparing the rest of the serial with records for the first manufactured pianos in each year. It covers Kawai pianos made from 1927 to 2020 in Japan, US, Indonesia and Canada. It should in most cases be accurate to within a year either way. This tool does not currently cover the hand crafted "Shigeru Kawai" pianos.
Kawai serial number :
Click herefor an idea of what this Kawai piano may be worth (via previously sold items on eBay)