Ray,

I seriously think that you better go back and re-examine the Supreme
Courts opinion as released in Haynes v. United States, 390 U.S. 85
(1968).  

Especially this little portion:

"We hold that a proper claim of the constitutional privilege against
self-incrimination provides a full defense to prosecutions
either for failure to register a firearm under 5841 or for possession of
an unregistered firearm under 5851."

You can find and read the entire case at:

http://caselaw.findlaw.com/cgi-bin/getcase.pl?court=US&vol=390&invol=85

The language is quite plain.  The ruling does not say that Criminals do
not have to register their gun, it says that the fifth amendment
provides a full defense to prosecutions for failure to register a
firearm under 5841 or possession of an unregistered firearm under 5851.

26 USC 5851 is a part of the National Firearms Act.

If you are going to quote U.S.S.C. rulings, please do so accurately.

Regards,
Wesley Horton