Yes, when I posted photos of mine with similar inaccuracies as yours, I was told ways the design will tell the "era." On the top of the seat stays you have the typed name, not the signature, from what I understand the signature started with increased production in 1982. This would also mean you should have the older decal set. Also, do you have a star cutout on your bottom bracket? If not, it would be an earlier frame too, somewhere between '78 and '81. And I think your Columbus decal should be for "SL."