Collectors of vintage jewelry love Victorian and other antique pins. They are highly collectible and generally are styled much differently than later pieces.
 
The locking C clasp was invented in the early 20th, so earlier pins would have the older style of C Clasp where there is no swivel and the pin just sits under the loop of the clasp.  If you have ever owned one of these, you will know that they are sometimes a bit "insecure" and the pin can come out of the loop, making it possible for the brooch to fall off.

Some of the very early antique brooches solved this problem with an extra long pin.  This pin extended beyond the edge of the brooch design far enough so that one could weave the extra back into clothing for security.  The pins were intentionally made this way to provide a bit of security that the brooch wouldn’t fall off.

Here is an example from my Ruby Lane shop.  It's a lovely mother of pearl and glass Victorian pin with this extra long clasp style.  I love the pretty turquoise blue glass "grapes", don't you?  This pretty pin is available in my Ruby Lane Shop - The Finishing Touch Vintage Jewelry, for $78.