The Givi arms on my 07 FZ1 have the part number 359FZ-KZ359, I have both base plates M5 and M5M. One base plate is for monolock and the other is monokey ( I think !). Either will fit the arms just depends on what topbox you want to fit.
Whilst both the pictures you posted show the same arms it also says on the picture that the "actual monorack arms may differ from the image".
But if you search for FZ1 monorack arms like you say both part numbers come up
The only difference I can find is that the 365 arms seem to be listed as for the FZ1N model and there is different tailpiece unit on the FZ1N to the FZ1S so whilst the arms look the same there must be some kind of difference. .