Nonc D

You have touched on many issues.

2 & 3 row button accordions are all diatonic (different notes for push & pull).

The main chromatic accordions (push & pull being the same notes) are the piano accordion, the chromatic button accordion usually with 5 rows (& 120 basses), the duet concertina, and a chromatic bandoneon (there are also diatonic bandoneons).

The 2 & 3 row button accordions give you more notes for both the push and pull but not all notes are available in both directions. Ex. on a GCF, high C is only available on the push not on the pull.

If you get a 3 row, make sure you get one with right & left shoulder straps, it really helps over the one shoulder strap with thrumb strap.

But the bigger the accordion the heavier it tends to be.

I have a few piano accordions that are near 30 lbs. - beautiful boxes but heavy (I nicked name one - beast).

If you want to know more contact me and I can go over more of this stuff.

C'ya.

Ron W