?? I don't know the expression "cop out"...what do you mean by it?

Anyway, I have written to Henry Doktorski and will report if I get some ideas.Wim Wakker - who originally came to concertina from the accordion too - has some notes on "finger-articulation" and "bellows-articulation" respectively at his website which are very basic but do correspond to the outlines of Herrmann and others.