Register markings are sometimes just completely bogus, for no good reason.
Look at the one below. This accordion was bought new in the early 1970's. It's a Crucianelli Super Video.
If you look at the register markings you would most certainly say this accordion is LMMH.
Well, nope, it is LMMM and never was anything else. Register markings, certainly in that era, were mostly "decorative".
These markings look nicer than true LMMM markings, so Crucianelli just used these.
It also saved on production cost, as the same markings could be used on the Baton which is LMMH (and which has cassotto).
