There's an indentation
or a jewel mounted on the bass note of the 'C' row to get you
un-lost, but you really don't want to ever get lost.


LOL

I have both the C and E basses indented on my 72 bass, and the C and B basses marked (jewel on C and tape on B) on my 120 bass (which, ironically, is actually quite a bit smaller than the 72 bass), and I still get lost.

The jump that gives me the biggest problems is the one going from the F chords to the B chords (or the other way around). On the 120 bass, because it's an unusually small accordion, I'm just barely able to keep fingers on the buttons for the move, but on the 72 bass, I have to make a blind jump for that chord change.