The problem with deviating from the 'conventional' naming of the rgn file of yyyy01000xxx.rgn [where yyyy is the unit's native HWID and xxx is the fw version] is that any other naming will force the flash. The conventional naming prevents flashing an incorrect fw boot.bin. There are times when we want to force the flash such as when doing a full conversion of totally compatible hardware when the PCB P/Ns match.
Unfortunately, US/EU 24x5 and ID 2465 are not the same hardware in the sense that you can simply cross-flash as you've found out. Such cross-flashing might be possible with some serious manipulation of the US fw beforehand, but it's certainly not successful unmodified.
Maybe our resident navigation software experts can suggest some other CPR for your now comatose unit. There is nothing further i can suggest. Without flashing in preboot or from the card, i'm all out.
PS: I think i'm closer to Bali than Perth [geographically and spiritually]. BTW, not a fisherman by profession are you? :lol: