Kgl. Kais. would probably translate to Imperial and Royal because the Austrian Kaiser Joseph was King (Koenig), of Hungary and Emperor (Kaiser) of Austria. Hofbuchsenmacher means gunmaker to the royal court.
I think it is a bit unlikely that Barella from Berlin supplied to the Vienna court. And the Austrian K.u.K is usually pronounced as "kaiserlich-königlich".
After 1871, the Germans also had their personal union of a Prussian king and a German emperor - and for a stout Prussian, his king would always come first.
Regards,
fuhrmann
