I'm no expert and there seems to always be an exception to what you know. Looking at your bike, I agree it's earlier than 1982. The lugging looks similar to what was on a Bianchi Sport Donna 28 I rebuilt some time back. I believe it's not actual lugging, and the lugs are instead part of the head tube itself.



As mentioned, the sticker denotes a low-end basic steel. I can't find an image of it at the moment, but I believe the serial of that bike was located in or around that same spot. Those @ symbols look like they were stuck onto the fork. Are they just plastic or metal stickers or something? If they are part of the fork, I've never seen anything like that from Bianchi (but again, I know I haven't seen it all).