That accordeon dates to the 90's.

Regal is also Galotta and a dozen other brands.

Is it tuned "cajun" ie Just or 12TET ?

just tuned I guess. 80's , 90's whatever. When I got it the reeds were half gone and all falling out, so I assumed 90's was too recent. I didn't want to pay to have the old reeds put in so I upgraded them.