I know they started making the 2320SL in 05 because that is when I almost bought one and it was a first year of the layout. I think prior to the "sl" designation you could get the 2320 without a bracket. However, call the factory and confirm..
I know what you mean about being too long for the slip. I added 3' to my boat and got moved out of my old slip and into a more expensive 24' one. That's okay cuz I love the bracket