Not making too much headway with this. Chips arrived, soldered on the the reverse side of the easypcb. Not able to get any sign of the flash being seen. One odd thing, the physical solder pad for the flash chip, pin 6 on my boards isn't connected to sck of the arduino pin 13 at all, just a bare solder pad. I've bridged this with wire, still no luck. Hmmmm...! More experiments ahead, good fun!