Hold on, I still have a master ball in my abandoned Heart Gold playthrough don't I... Yeah, I do, I pretty much always end up hoarding those things.
With most of my team in that game having been transferred to later games (of particular note, an Umbreon I was using there actually wound up getting transferred to Platinum because it's bulky and can learn mean look which is of immense use to me for the post game bird hunt.) I don't exactly have enough of my main mons left to clear through Kanto which makes that save relatively useless because I can't use that to get the legendary birds.
Except I can use the Master Ball to nab myself a Lugia so I suppose there's that silver lining.