L3 grade has been discontinued a long time ago. I've only seen photos of one such pipe.
Here.
Ser Jacopo did indeed use a red coral dot on the stems before 1997 when they started using the silver "J". The dot was either a simple coral dot, but also sometimes found encircled in a silver ring.
However, there are two current “seconds”, or affordable lines of Ser Jacopo that are mostly seen in the European market. They may have fills or other small faults. Both carry a red spot on the stem.
La Fuma is a better of the two and have a red plastic dot on the top of the stem. Often have silver rings or mounts. They have "Ser Jacopo" and "La Fuma" stamped on them. However, all the La Fumas I've seen in person, the "Ser Jacopo" stamp is in sans-serif font, and not in script like the "regular" Ser Jacopos do.
Example.
Modica is cheaper of the two series and have a red plastic dot on the side of the stem.
Example.
OP's pipe has the "Ser Jacopo" stamp in script, so that makes me think that it's an pre-1997 pipe .... unless it has a "La Fuma" stamp.