Saw in a Gunshop- Opinions?

[Mauser720]

Regrading "the law" pertaining to Luger pistols having their stock lugs ground off, the following appears on page #394 of the book "Small Arms of the World" by Smith & Smith (copyrighted 1969):

"Many Lugers have their grips ridged for shoulder-stock holsters and the following facts should be brought to the attention of U.S. collectors. Possession of a pistol which is ridged or slotted for a shoulder stock and the stock which fits the pistol, requires under U.S. firearms laws, that the weapon be registered with the Firearms Branch, Alcohol Tax Unit, U.S. Internal Revenue Service, the branch of the U.S. government which registers submachine guns and machine guns and enforces the National and Federal Firearms Acts. Failure to register this type of weapon with the above agency can result in fine or imprisonment, and at a minimum considerable trouble and embarassment. It should be noted that in addition to the Federal statutes, most states have similar laws."

I am "new" on this forum, and also a new collector. However, I assume this law must have been changed at some point. I am guessing this helps to explain why some Luger pistols have the stock slots on their frames ground off. Personally, I think it is a real shame. Anyone else have more information on this?

Ron