Was the quality of Colt in the eighties bad?
Kind of a blanket statement and it ain't necessarily so. I have a 1984 production Colt single action that I bought NIB a couple of years ago. The fit and finish on it look as good as any other Colt single action I have seen. It is reasonably accurate (I can't see that well anymore) and has as good a trigger as the second generation Colts I have handled.
All that being said, I would not recommend buying any gun without inspecting it first.