squeeze me, I disagree ,in my experience 26 key lachenals[not jones] are of reasonably good quality and have actions that are better than most accordion reeded concertinas.
One indicator, apart from the use of ears and playing the instrument, is the detail in the fretwork, a good rule of thumb is this the more intricate the more likely it is to be better, mahogany concertinas were generally the cxheapest rosewood were the next up the ladder
Brian,it is not snobbery, the sound is different, the reasons were explained by steve dickinson, you are wrong but do not have the grace to admit your error.
I gave an example of Bellamys playing which on the occasion was a song that could have been played on the 20 key, the op seemed to express some sort of experience of Bellamys playing, the clip seemed appropriate.
much depends on how much money the op has to spend.