dvid,

1) Rom failures are usually shown up when the ecu has been chipped.
This is perfectly normal in this situation provided the car runs ok.

2) You can have your existing ignition keys reprogrammed into any ford ecu
but this will have to be done by a ford dealer and will cost about £40 per key.
As long as you still have your original RED ignition key otherwise it will
be an extra £80.
(all prices approx)
Assuming the ecu is compatiable with the car.
As its only £10 on ebay its a reasonable gamble !