Hi,
I know this is an old thread, and I have a very limited knowledge of anything other than the French musette style. One player that springs to mind is Louis Camblor, who is a French Basque accordionist.
He plays a mixture of tunes on the usual 3 voice French musette style accordions, although paso dobles and other Spanish tunes feature strongly in his repertoire. You'll find him on You Tube.
His style is definitely not to everyone's taste, unless you also like Basque folk music, but you may like some of his tunes. I doubt whether you'd recognise any of his stuff, and that may put you off. Also, the scores may be hard to come by, if you can't work them out by ear.
Like yourself I've hunted long and weary for Spanish accordion recordings without much joy. There are one or two players who have made a handful of CDs, but nothing spectacular. The only tunes that seem to be popular for Spanish accordionists are the Spanish classics and they are certainly not easy to play, as you are using Spanish and/or Flamenco guitar chord progressions, that don't fall easily for accordion bass.
The same might be said for Portugal, where the CBA is reasonably popular in the Algarve, but perhaps not so much elsewhere. If you listen to tunes called "Corridinho", these have a strong Spanish flavour, but obviously they are not Spanish.