Gee, that did not take very long to get an answer, 9 days after my post. Good for the people that have had it with .goob and stood up against them.
You already are a Felon just by possessing it, so what is the big deal about the Serial Number? Either dump it, build it up and stash it away from you location, with no possible connection back to you, including FingerPrints, and DNA, OR DeMil it, or send it to ATF... I mean... "duh".....
Jeez, If I can remember where my boat sunk I'll make a dive to check if it has a number.................Nope, can't remember. Oh well.