ak12r,
All legalities aside, I admire your persistance in trying to find the buyer who paid in full. Since there was no agreement to store the bike, and your circumstance in having to move, I believe the bike is yours to do what you see fit.
However, I see a moral dilemma. Considering the buyer was a military man, who knows what he was exposed to. My suggestion is to sell the bike(if it ends up becoming yours again), and donate at least half the money to some veteran charity. That way, you get compensated for our efforts, and the veterans will be honored for their services.
Put it up for auction describing the situation and see what happens!