Unique Mailing Situation. What Would You Do?

Be careful. Do not keep his money. Return his money after a set time. Do not sell his parts unless you have proof positive he received his money back less any fee's you had
Do not do family and friends with this guy, eat the PP feel or add it into the cost of the item
Your got lucky you kept your parts and got paid, could have went the other way.
Give him a couple of weeks to get his act together or return his money and walk away
He may have some life issues more important than parts but thats not your problem