James Jisaka's Yamaha FG-360

My name is James. I ran across your post on the FG-360 and it sparked my interest. My father-in-law was Japanese and I have since inherited his guitar. I don't really now much about it, but it's a Japanese model with the serial number 20624508.

You mentioned in the article that the first five number denote the date, which I guess makes it from the 24th of June, 1976. Do you have any idea what the last numbers mean? 

I'll send a couple of photos along if you're interested. 

Cheers,

James