This might sound dumb, but....

Perhaps your Indie could buy a lock assembly from a wrecking yard? He could clean it up a bit inside with some cleaner and lube it with some 3-n-1 lock oil and then install it.

You would know it was working well when it was pulled so there would be no question of if it was in working order when you received it.

Not the most graceful solution but it might be the best one.

And if no wrecking yard near you has one then Ebay is always as close as your keyboard.