If I can find the time, I will listen to the CD again and figure out which kind of accordions I think he is using.
It is definitely true that he used single row and triple row the vast majority of the time.
Even though he's holding a chromatic in that picture, I really don't think he used it much at all. It was probably more of a novelty type thing.
I bought a really nice chromatic a long time ago. I figured out how to play it a bit, but never gigged with it and I don't think I ever will. I really ought to sell it.