The guitar-like instrument being played alongside the accordian in the tavern is a mystery.
It is the size of a guitar, but it has waists/C-bouts much like a violin.
It has a wide fretboard, there appear to be five paired strings,
and ten tuning pegs (or possibly five that extend through the entire head)
that protrude horizontally (like a steel string guitar),
but the head has two parallel slits (like some gut string guitars).
It's definitely not a lute. In the film the player strums it, doesn't pick single notes.

the guitar-like instrument in the film

a typical classical guitar, showing parallel slits in the head

a typical violin, showing C-bouts on both sides
Those wooden pulley devices on ship rigging are called "blocks" in nautical context.
These devices are very commonly seen on keychains in nautical gift stores.
Note the whale tooth on Beckett's desk in the background. The carving on it is not visible, but in all likelihood it's scrimshaw.
A foreyard is the lowest yard on a foremast.
Created: July 13, 2006
Updated: April 19, 2007