I had a Cajun King and they use a larger size bass box. When you are ready for an upgrade, look at different accordions built in LA and TX. Look at the bass side. If the bass box is the same width as the strap then it is the smaller size. If it is wider then it is the larger size. After one year of playing, you should be ready for a handmade box. Contact some of the builders on this forum and I am sure they can accommodate you. You are in good hands here. Good luck and keep squeezin'.
I agree, I think I'm ready for a custom built accordion but my wallet isn't. I'm still about another year out from having enough saved up for one. This one will have to do for now, so I'm curious to see if there's anything I might be able to do to make this one work for now other than not learn songs that require the regulator!
I suppose the 2 sizes being referred to are 2" wide, and 2 1/4" wide. Even with the smaller size, there are several options for smaller hands. The top can be rounded off more, making it narrower. The box can be made a little narrower than 2". The buttons, which are usually put in the center, can be moved up toward the hand a little. All of which will make it more comfortable for a smaller hand.
A friend of mine has smaller hands than mine (shorter and thicker), and he had a smaller bass box made for his Regal (later model Regal. I have one too. Possibly a Weltmeister knockoff).
Another friend of mine built it for him. You don't need to get the current one refitted. You could get an alternate one constructed, screw that one on, and when you're ready to sell the box, put the old one back on.
Just have to find someone to make you one. I've never made one. I think the hardest part would be fitting the baffles and dividers in the inside, not the construction of the outer frame.