It’s been several months but this may be of value to others. I don’t recall being aware of this when I originally posted but deep in the P73 owner’s manual is a table of memory that can be used with the camera (it includes the caveat that there’s no guarantee of proper operation). The table entires were:
Memory Stick
Memory Stick Duo
Memory Stick Duo MagicGate
MagicGate Memory Stick
MagicGate Memory Stick Duo
Memory Stick PRO
Memory Stick PRO Duo
I bought a used 4GB stick labled Memory Stick PRO and MagicGate. It was slightly snug when being inserted. Also the display screen initially showed a blue image that I’d never seen before - possibly because I’d never before used an empty memory stick. But it seems to work fine. 4GB is a massive amount of memory for this little camera.
