Honestly (and this is just my personal opinion) there's nothing on the shirt that says I served etc so as long as if you're asked about it you say something along the lines of I'm not a vet but respect those that are I wouldn't see any problem with you wearing it.
Just spoke with my grandfather and emailed the donator so if I don't hear back tomorrow I'll call directly. Should I use this thread for all other donation products or start a different thread. I would like to keep a continuous supply and demand going.