Riva:
As some of the chips worked but not all I wonder if they have been programmed already (grey imports?) and need an external crystal as fuses have been set for that. Adafruit have an ArduinoISP2 that can supply a 8Mhz clock signal from an UNO pin that is maybe good enough to reset fuses.
Another possibility is the fuses have been set to disable Reset pin or ISP. I think you would need a high voltage programmer to fix this problem.
RIVA: I looked at the chips under a magnifier and they are all marked ATmel ATtiny85-20PU. The Mouser catalog only shows the max speed as being 20MHz. The 230 page data sheet lumps the tiny25/45/85 and I get lost in the details. I will look at the Adafruit option and order another batch of theTiny85s and hope. Thanks!
Still gonna keep trying, though 8)