With a little help from my friend/avatar

[wirralaccordion]

 

[dak]

I am not sure why you call this a piano accordion. The treble keyboard tray depth and corner angle rather strongly point to this being a button accordion.

 

[tcabot]

A second what dak said. This is a CBA.
The depth of the bass section suggests it's an orchestra model, i.e. treble-only.

 

[dak]

A second what dak said. This is a CBA.
The depth of the bass section suggests it's an orchestra model, i.e. treble-only.

Schrammelharmonikas have their bass buttons straight on the side, like concertinas and bandonions. A Schrammelharmonika is CBA on the right hand (B system) and has diatonic/bisonoric basses on the left.

 

[craigd]

Very astute dak, also, when I listened carefully with my eyes closed I perceived a somewhat different tonality from a piano accordion.