JohnCushman
Well-known member
On facebook here in my local area there are buy/sell/trade pages for the area and free stuff pages and things like that. Perhaps you could join the ones in your area and post that you found a GPS and see if the owner is a member of those sites and could get ahold of you there and give you details about it to prove that it's his. If it's not a local, then they'd be shit out of luck with that idea. I would go with the warranty registration idea as well.