Until now I only saw an advertisement for a 6530-005 in an 70ties magazine. But today I found an ebay advertisement selling these IC’s. A Rockwell variant, date code 8114. Without any description, so the function is still unknown. But a photo is now found!
I also found more 6530 variants used in the pinball industry:
6530-12 or 6530-13 were used in the Gottlieb System 1 sound boards
6530-14 was used in the Gottlieb System 80 series sound boards.