Not sure if the owner could be found since Walmart shares the parking lot w/other stores; but I did drop off the flash drive to Walmart customer service just in case someone goes there looking for it. I'd hate it if I lost a flash drive! I did copy the image files though, hey, I found the drive
I did do a test of installing, playing & uninstalling each image at separate times & both work identically. So I'm probably keeping the .iso since it's smaller & just 1 file.