Need Info on GP Gyromatic

Hi,

This is my first post. I hope someone can help me. My Grandmother gave me a GP Gyromatic that belonged to my Grandfather. It was given to him in 1967 by his employer for 25 years of service. I know this because it is ensribed on the back. I had never heard of GP before and wasn't aware of its highly esteemed(?) history unitl I did some research on the internet. Anyway, I was wondering if anyone could give me info on it. The reference number engraved on the back is 45193F. It has a silver case and a champagne colored dial with date window. It's probably worth more sentimentally than monetarily, especially in its present condition. It is in bad need of a crystal replacement and a new band. He put one of those cheap old-man stretch bands on it. I know it's not original because it says USA on it. I wonder what sort of band it originally had. I'm thinking I might put a brown alligator style leather band on it. Please let me know if you have any info on my watch.

Thanks,
Bret