The MCS6530-005 was known to me only by some lines in MOS pricelist and a remark in an OSI appnote as a 6530 without ROM.
It is therefore no RRIOT but a RIOT (RAM I/O Timer).
I have acquired several MCS6530-005 ICs and tested with the Backbit Pro Chiptester V2 and indeed it passes all tests of the 6530 except the ROM test.

Today I received a scan of a MOS Technology sheet with the chip equations of the MCS6530-044 and MCS6530-005 (thanks Scott Barnes!).
No CS1 and CS2, just I/O PB5 and PB6.

Now the mystery of the-005 is solved! See all 6530 information here.

MCS6530-005 Chip Select Equations (thanks Scott Barnes)