Use them to make stepping stones for your garden. Use "QUICKCRETE"
and aluminum cake pans to make the stone and just before it completely sets up, put the guitars on the top and push them down into the mix. The rubber guitars will keep you from slipping on the stones. Take the rings off before you put them into stones and use them for other projects.
On your sewing machine, make mini drawstring bags to tie around the guitars. They can have parking meter change in the bag.
Lots of great suggestions...you sure have a boat load of these!
Donate to a local VFW hall or any guy club in your area. Meals on Wheels can use them to give to men on route .
embroider FSL guitars (pretty sure Yoriko has one) and glue them over the advertising logo. Print "you rock" or "I pick you" or "you're music to my ears", etc on the back and use as love notes and thank you's ... ;)
I like your idea, and I do not think we have met, I am Christine. Thanks for posting.
I don't have any additional ideas because I can't think past what guitars and motor oil have in common? What a strange advertising campaign. LOL
Cut off the guitar & use the keyrings for some you've made yourself! Either FSL or other. Or the fsl initial.
Looks like a lot,make up some denim pencil bags and use them as zipper pulls.Put them in easter baskets,give away to the guys. Or if you have a lot of keys use them as intended.