Can someone help me identify this old Yamaha Soprano?

I'm trying to find out more about a friends ukulele... here are some pics, any info is GREATLY appreciated...

It was found in a friends attic and apparently sat there for 30+ years. My friend is good at wood working, and has cleaned up the finish in addition to fixing the bridge, which had fallen off. I believe he re-strung them with worths as well. Intonation on this thing is great and it's the easiest soprano I've ever played. It even has wooden friction tuners...

It's number #80 since I understand that part may be hard to read and the Uke case came with some 1925 "Learn to play the uke in 5 minutes" brochures...

Thanks!
RickyRicky

Here is something similar, but no real information:
http://www.frets.com/fretspages/museum/Ukulele/Yamaha/yamuke.html

As good as this thing sounds compared to an old Lanakai I once had, I have a hard time beleving it's a cheapie...