OK so anyone shed any light on my particular brand of self-doofication?
Grabbed PRSCustomize and dived in head first - did something wrong and bricked the reader....
No Worries, reflashed using the normal method and now it has US 1.1.00.18040 and works fine.
Tried it again (because I didn't kill my reader the first time
) It builds the image fine (option 5) and flashes it fine (option 6) reboots all round....
...but...
It doesn't actually seem to make any changes, I still have US1.1 despite picking UK 1.2 and none of my customisation seem to "take".
Didn't try anything fancy like icon or font changing just About details, clock, numbers off in books and uniform font size.
I've had a look round the forums and to be truthful I am not sure what I am searching for to find it.
Any hints will be gratefully received.