The first thing you need to know is that "baritone violin" is the name given to two distinctly different instruments. The first type of baritone violin, arguably the legitimate claimant of the name is a member of the "new" violin family known as the Violin Octet. The baritone of this family of instruments is a huge instrument, with longer string length than a full-size 'cello. This is not the instrument that this site is about; however, if you wish to learn more, take a look at:
• The official New Violin Family Association website (http://www.nvfa.org/)
• The New Violin Family: Augmenting the String Section
The second type of instrument often called a baritone violin is the violin-like instrument played under the chin, which is played like a regular violin, as it usually (but not always) has the same critical ergonomic dimensions as a standard violin. This is the type of instrument that Don Rickert Research & Design™ designs and builds, as well as its collaborating firm, Fiddarci Lutherie™. This type of instrument is properly called an "octave violin" or "octave fiddle"