Great box. I have two, FBE and GCF both bought used. I believe they are Guerrini's that Castiglione has made for them. Both are three treble 5 bass reed. The only design flaw is the treble switches. They are prone to be hit accidently as they are kind of close to the inside row. Dikki Du and Nathan Williams jr. play or played them. Hope this helps.
There is a good close up video clip of Chubby Carrier playing some bluesy runs on his Gabb. I found it on the forums at the Reyes Accordions web site. I still haven't purchased a triple row, nor have I even held one. Soon, very soon though. I'm waiting to see if I can get a sweet deal on a new Panther. Two reeds per note, but I'm no pro. Check out the used accordions listed in the forums there as well. I like playing Cajun music on my La box, but I also want to crank it up with my blues brother (literally)on occasion.