Well Guest(s), are you one and the same? Time to get yourself(ves) a proper user name?
To answer the question about JK's button accordion (as he describes it, to distinguish it from his 2-row melodeons), the best place to find the right answer is on his own website, which I'll quote from now.
"John Kirkpatrick leads a series of workshops for players of the three-row button accordion - the quirky instrument that was taken round the world in the first class hands of Jimmy Shand. The right hand gives you three melodeon (push-pull) rows in B, C, and C#, and the left hand side gives you full accordion basses in the conventional "Stradella" layout, with bass notes and chords that are the same in either direction."
There are other current players of this strange beast, not just the late lamented Jimmy Shand: up here in Scotland, the piano accordion rules supreme, but there are other bands and players who use a similar instrument to John's e.g. Robert Nairn, Norman Mackay. The left hand stradella base is more like what you find in a piano accordion with rows and rows of basses, and, as it says above, same chord in and out. The instrument does make a good big noise, hence very suitable for dance bands. My two-row B/C can be quite loud, but far fewer options for bass playing than with stradella bass: the right hand has a range of over 3 octaves.
On John's website, there's a nice picture of him with his array of instruments: the one we're talking about here, is that one on his knee: John Kirkpatrick
I should have also said before that one of the joys of going to his workshops is picking up the tips he gives on how to give your playing that lift for dancing.
Ok, I'll stop drifting and get back to thinking about fiddles, Guest 2.