Bernard, I would love to get one of those. I have several 'reed organs' some of them have small Stradella bass sections - most need the blower motors replacement - working on using 12V computer fans.

I am also looking for the 'clavichord' which was made - some forms even came in 'roadie proof' (and that's saying something!) cases - used by some pop groups.

As for piano accordions, all you really need to get started is a 32 (8x4) bass - or a 48(12x4, not 8x6) if you really want to play in a few more keys. Much lighter and smaller. 72(12x6) is really almost 'full size' (20x6) in terms of physical size, abilities, and weight. Unless you can get a 'miniaturised' form of 120 bass - I have a couple... :-)

I have prepared a small "guide to the accordion for recycled musos' guide which is in a thread here.
http://www.mudcat.org/thread.cfm?threadid=63945

Also on Wiki a group of us has been working on the Accordion article - with all its sub articles - piano accordions, etc. Starting to look quite good now, lots of history and references.