Bear with me if this is a dumb question....

What are the rules for when Import Marks are required.

I see some items advertised with "No import marks."

Two questions:

1 - Is this legal or does this mean the item was imported before some law stated import marks were mandatory?

2 - Within the C&R book it requests the Importer or Manufacturer. What do you enter if there are no import marks?

 What he said, with the addition of...

Early import/export marks was only a mark of the country of manufacture.  If you look at an old mauser and it says Germany on it, that would be an import/expot mark.

The current law requires marking of who the importer is and an addy..

FMO

There are a couple of reasons an imported firearm may not have an import mark.  I could have been imorted before the marks were required by GCA 68 or the import mark could have been removed by an individual owner after import.  There is no legal Federal requirement to maintain the import mark once it is sold in the US.  A lot of state laws forbid the removal of "identification markings" though.  I don't know if import marks would qualify or not.  Until recently, most of the import marks were on the barrels of the imported firearms.  If the firearm was rebarreled, the mark goes away.

In the bound book entry, if you don't know the importer, just put unknown.  By the way, the regulation requires both the importer and manufacturer, not just one or the other.  The illustration of the layout is misleading.  The text of the law and the regulation require both.