Wow, you guys are way too nice. Heck even most banks refuse to look at any thing older than 90 days.
Where I work, at a small computer shop, we have a firm policy that if it's there after 30 days from completion, it becomes our property. We only get about 2 dozen systems in a week to work on, but every Saturday morning I confiscate 3-4 systems that are greater than 30 days old. If we did not do this, we would have system so piled up, we would need to rent a storage unit to deal with them.
Of course the difference is we have the customers sign paperwork stating as such.
Now, that being said, since it seems to be over 90 days I'd give one last contact with a hard date (1 week, (Don't be generous with a long hard date, he doesn't deserve it)), and claim it. If he ever wants his money back, tell him to request a charge back via however he charged you. If whatever payment agency accepts it, don't fight it. But I would be very shocked if his charge back is approved.
I know it sounds harsh, but this guy is not a friend. He's a customer / business acquaintance. One should treat him as such
Steven