You cannot operate a Hammond without the shuttle. Initially the shuttle was split, right down the middle, and upon pressing a key, the correct character’s shuttle segment would swing over, and receive pressure from the hammer. These broke easily and were more complicated to make.
Then around 1898, the Anvil & Shuttle model was introduced, with a one-piece shuttle, which significantly simplified operation. The new shuttle is an arc of about 118.2 degrees made of hardened rubber, with a thin metal spine on the inside of the arc. The characters are arranged with the symbols and numbers along the bottom row. When the key is depressed, the type select arm shifts the entire shuttle around a metal ring. This shift aligns the proper character with the hammer.
Each shuttle came in a small dovetail box with sliding lid. Typically the catalog number for the “type” or its name was written on the lid. The new shuttle design led to a new machine, The Anvil & Shuttle, which used a metal ring with a horizontal cut so that the hardened rubber of the shuttle could slide along the smooth face, driven by a select arm. Quite ingenious design.
Below you will find PDFs of later shuttle guides and lists. To identify which shuttle you have, a number is almost always stamped with the characters. For example if we zoom in on the shuttle above we see it has the number 40 pressed into it. Looking that up in the shuttle list we find its description.
These guides can help you match the shuttle to its font.