Yes, yours could be old stock late registered. But it's not really late as if you think how long it took to come from Japan, it is probably correct. You can find out from Honda UK when the bike was manufactured but that costs about £35 and you being a tight Yorkshire git 🤗 even though if you could prove it was manufactured before Jan 79, by the time you find all that out, it will be April 1st and FOC tax. So unless you want to find out just for your own inquisitiveness, I wouldn't bother.