I think we want to keep that one, as it provides immunity from prosecution for transporting guns across state lines, when the guns are legal between the starting and ending destinations. For example, suppose you are transporting class III weapons from Texas to New Hampshire. The McClure-Volker Act would prevent you from being prosecuted by anti-gun prosecutors in New York and Massachusetts.
After a quick scan of the web, it turns out that my reverse chronological reversal left out other affronts like the 1996 Domestic Violence law, and of course the Brady bill.