Hitachi ex100 questions

So I gambled a bit today and bought an ex100 that is missing a starter and possibly has other electrical issues. Where can I find the serial number to determine what machine age is? It has the isuzu motor. It is tagged bd1pz but looks like it is missing the first digit. Is the electrical system all 24 volt? It is also missing the batteries. What is a good source for a new starter? View attachment 177111

Hitachi ex100 questions