Hollow handle items are made from an original handle in your pattern with a new stainless implement. Then the piece is hand-finished by a highly skilled silversmith in the USA. Now that many sterling patterns have been discontinued, custom pieces have become a staple in the sterling silver industry and are widely offered by mainstream sterling flatware dealers. Why isn't a Hollow Handle piece marked/stamped in any way? Yes, the hollow handle is sterling and a genuine handle in your pattern, even though it is not usually stamped.
Hollow handle items were usually not stamped due to their hollow construction.