Couldn't the slightly changing cockpits be chalked up to advances in the tech? Life support systems, ect.? And looks like Wedge likes listening to some tunes while flying around, so he had better speakers installed behind his chair ; )
Oh and also in regards to the OP, Jabba and the blues makes sense in my mind. Jabba and a horrible CGI Las Vegas show-tunes band doesn't. That new song HAS. TO. GO.