Create a staff template for the Chemnitzer Concertina

It is possible, but requires a lot of work. Here are the steps that work, at least in MuS 3:

• Create a new score from the 'Grand Staff' template. You'll need about 10 measures, depending on the paper size.
• Insert a staff break in each measure
• Open the staff/part properties for the treble clef, deactivate 'Show time signature', select 'small staff'.
• Open the staff/part properties for the bass clef, deactivate "Show time signature" and "Show clef" and reduce the number of lines in the style group to the value "2".
• Now the size of the staves can be a little small, so use "Format -> Page" and increase the scaling.
• Select all rests (right-click on one and select "Select all similar") and hide them.
• To make the last measure at the bottom of the page fill the entire page width, use "Format -> Style -> Page" and set the "Last system fill threshold" to zero.

See my version created with 3.7. in the appendix. Maybe not quite perfect ...

EDIT: Yes, at least the measure numbers should also be hidden.

In "All instruments" (down arrow next to "Common") there is a concertina instrument. It is a full treble and bass clef instrument. Open that score and select the first measure of the bass clef. Right click and select "Staff properties". Uncheck "show clef" and "show time signature". Select "Advanced style properties" and reduse the number of staff lines.