There are a number of music sites selling the Baton Rouge box (£5/600 approx)and...would you believe it..I have just looked on ebay and one is due up...currently running at £130 with a day or so to go.
My feeling is that unless you have experience of particular boxes you could end up with a pig in a poke !!
The present box is just a very cheaply (£15 !!!) bought thing which has allowed me to quickly get the feel of the single row and bellow rythms. I am surprised how easily I have picked it up playing by ear (that will be the fiddle I guess) but the box is in G and although a very tight good sounding box (for Morris/English traditional/etc) it has it's limitations and as I really want to play Cajun I and am not getting any younger feel I need to decide soon and buy !!
I will contact all the sites you have all mentioned
This looks alot like the excelsior Acadia. This one on ebay UK even says Acadia on it. i don't know alot about these other than the stops are pushed down to open rather than the traditionly up to open on a LA box.
I see what you mean Sambeaux..just looked up a model...very similar !!
I suppose the problem of so many accordions being given different names when they've all been mass produced does tend to lead you to seek out the genuine hand made makers even though the waiting list can long. Been in tough with a guy in France (Martin) and he has a 15 month waiting list !!
The advice about finding a good second hand one from one of the top makers is sound...if....you can find one !!
The Finnish accordion is the real thing. Look closely spacers under the keyboard means he is using return springs. The corner sets are the same as Larry Miller's, the closure straps are the same as Larry Miller's, Butt joint construction, same thumb and base straps, buttons etc. All are quality parts. The fact that some of the accordions are shown with the stops closed does not mean they are chinese. Look closely 2 are open (stops up).