Wouldn’t the easy route be to find someone who was convicted for posession of a post 1986 weapon and go to the court to get the conviction overturned?
http://en.wikipedia.org/wiki/David_Olofson
So far, no one up the chain in the judiciary wants to hear his appeals.
All for a malfunctioning rifle he loaded to someone else in working condition.
Not likely to succeed. Google "enrolled bill doctrine."