From the Notessimo V3 SoundFont
Have the cornet and euphonium been included in the next version(s)?
This is the best image for the former found on the web, just rotate it left (counter/anti-clockwise), shrink-resize, and crop to nearest outlines: click here
This one could work too, realistic but seems to be a marching euphonium: click here
Hopefully the rest of the marching band instruments do too; currently transcribing the finale of the 1812 Overture using one of either .PNG linked.
Thanks again!