Giannini guitars and how to date them.

[davidnyc64]

Hi forum, I picked up a Giannini guitar at a yard sale for $17. I cleaned it up and put on new strings. It's a smaller body, so I'm assuming that it is a student guitar. I can post a photo later but I was wondering if anyone knows about Giannini and also how I can find out how old it is and also I need to replace the nut as it seems to be worn down.

Thank you,
David