I have to agree about the Chanel-style suit. Man, I even remember the Debutante's Guide to Life talking about that. Maybe one day this will no longer be true, but for now...
For the most part, I don't think any specific item of clothing can be pinpointed as aging or age-inappropriate. It's more a combination of the clothing and the individual wearer. Something in the chemistry between person and garment. Maybe, tho, there are some styles that get along with more people than others.
I mean, the only person I know who looks hot in St. John is Angelina Jolie, and I really don't know how she does it. I'd seriously like to know.
And yesterday I saw this woman in 7-11 dressed like Tia Maria Torres (from Pit Bulls & Parolees on t.v.). I think she may have been of similar age to Tia, but whereas Tia looks natural... I must confess, I hope not unkindly, to experiencing cognitive dissonance with the 7-11 lady on the matter of her age v. her clothing. It's on my mind because I realised at the time that I wouldn't have blinked twice if she had been Tia...