This is a roller type rastrum which harks from the "Stravigor" rastrum which was conceived by the famous 20th century composer Igor Stravinsky. Two felt-like sponges are presses against the rollers by a spring held within the housing and is soaked in stamp pad ink. The wheels collect ink from the sponge and transfer it to the paper when rolled along a sheet of paper. The advantage of roller rastrums over other types of rastrums is its ability to draw consistent straight lines without the aid of a ruler. Ballpoint-based staffwriters like the Noligraph require a ruler and often have inconsistent lines should even pressure among each pen not be achieved. This is why I believe roller-based rastrums are the superior tool of choice. More information can be found here: http://www.baltimorerecorders.org/handwritingmusic.html

Before computer software reigned supreme in the late 1980's and 1990's, music copying and engraving was done by hand. One method of engraving was by using stamps. More information can be found here: https://musicprintinghistory.org/music-printing-stamps/

This stencil is used to draw various notes, clefs, articulations, and other diacritical markings. The kit comes with the stencil, a handbook on engraving, an instruction sheet, and a Pentel 0.5mm mechanical pencil. Scans of the handbook and instruction sheet can be found here for your reference: https://drive.google.com/drive/folders/1ctn6CXep3BUQKgyiKbrwcvfrHXbSQjyR?usp=sharing

Music nibs have been around for over a century. Their main purpose is to replicate the look of a printed score by hand. Music nibs have an italic cut, which means the tip is cut flat. The composer or copyist holds the nib at a 90-degree angle to the paper in order to achieve thin downstrokes (for note stems) and thick cross strokes (for beams, flags, slurs, etc.). Music nibs also flex when pressure is applied. This allows for control of slurs, noteheads, dynamics, and other diacritical markings. While not a requirement, many music nibs will be double-slitted to aid in flex and ink flow.

Most so-called 'music' nibs today (Platinum 3776, Pilot Custom 74 etc.) are glorified italic nibs since many, if not all, do not flex. The Noodler's Neponset being the worst offender, by simply cutting 2 slits in a standard nib. The Neponset nib is not italic, nor does it flex (those that say it can flex are to be taken with a grain of salt) therefore it fails to be a music nib.