I have a small collection of the MOS 6530 RRIOTs as made by MOS Technology.
Mask programmed, ROM and also ports can be used as chip select. See the 6530 pages!

I have tested my 6530s with the excellent Backbit Chiptester Pro V2.

6530-002 black all tests passed and ROM dumped OK, confirmed to be the 002 ROM, main KIM-1
6530-002 ceramic all tests passed, ROM test fails
6530-003 black all tests passed and ROM dumped OK, confirmed to be the 003 ROM, audio cassette KIM-1
4x 6530-004 all tests passed, except the PORT B and no ROM dumped, TIM
3x 6530-005 all tests passed, except the PORT B and the ROM (which is to be expected, the 005 has no ROM)
2x R6530P/R3004-11 all tests passed, except the PORT B and no ROM dumped, pinball
2x 6530-24 all tests passed a except the PORT B and no ROM dumped, Commodore diskdrives

I also tested a 6530 replacement, built with a 6532 and some glue logic and an EEPROM, both 002 and 003 variants tested OK.

SO I suppose all these 6530’s except the ceramic 6530-002 are all right. The Port B test fails, since the 6530-002 and 6530-002 use pin PB6 for a chip select and the others may have this as I/O pin. Now waiting for an answer of the Backbit Chiptester Pro to my query about Port 2 testing.