Hi Colin,
I know what you mean about accordion shops. Up here you can walk in looking for an LMMH to play swing and jazz, and they'll tell you they only have LMMM with Scottish musette tuning, but you can play anything on them. There is always pressure, but at my age now I just tell them that if they haven't got what I'm looking for then I'm off like a whippet. If I was honest, electric guitars are a bit of a challenge to buy in a shop, and I've bought most of mine online. They'll always find some kid who can play as though they have 17 fingers on each hand, then stand back and watch you fumbling through the repertoire you can never quite remember.
I recently decided to take a few CBA lessons to help me get rid of several thousand bad habits I've taught myself. My teacher has several accordions and uses a swing tuned Bugari to accompany me. Very nice sounding box, but I've never had a go on it, as I'm about twice his size and it would take the whole lesson to adjust the straps. He also has a Borsini Orfeo, and he prefers the Bugari. Now I don't know whether he prefers the Bugari because it has a stepped treble keyboard, whereas the Borsini has a flat keyboard. He plays Swiss Landler music and also uses a Paolo Soprani with a flat keyboard for that purpose.
As a dyed in the wool musette player I obviously had a preference for French accordions, but with the passage of time I would say that the Italians make a better instrument, and it's up to the player to work at getting the desired sound. I have been thinking of asking him for a go on his Borsini, which he's trying to sell, but his Bugari is definitely not for sale.
Therefore my music teacher, who has been playing for 50 years, prefers Bugari to Borsini (or so it would appear).
You've obviously reached the stage where it has to be one or the other, which is fair enough. Personally speaking the make wouldn't matter to me, or any perceived quality issues associated with a particular make. One of my Cavagnolos (which I bought new) was the typical Friday afternoon job, and the other one has had a very hard life with tired old reeds, , so other people have had better experiences with it than I have. I recently had my Maugein Mini Sonora refurbished by the teacher, and although he wouldn't want to have received it in a lucky bag (it's a smaller 96 bass accordion with less treble range), he acknowledges that the reeds in it are superb.
Just another thought. If the one in Scotland is LMMM the musette will be very strong indeed, but that's how some players prefer musette to be, as I'm sure you're aware.
I'm sure you know what you are doing, and wish you well in the venture.