I'm assuming you mean the aftermarket multi-lug no-vent rim that's usually chrome and has a pressing around the center around the hubcap. I first noticed them in the 80s, but they might be from the 70's There's all kinds of aftermarket chrome steelies, I have a couple of aftermarket chrome rims that were on a 40 sedan my dad had for a while in the early 70s that almost look like reversed Ford rims. I've never seen actual "Smoothies" like you can buy now on a car in any old magazines from earlier than 1980 or so. I think that kind of thing just popped up in different versions over the years, so if you use them on a car that's supposed to be era correct 50s or early 60s, I think they are incorrect. If you're just putting them on a lowered late 70's Chevy pickup or something, then they look great.
Yeah like many of the terms used today, some terms take on a new definition. I remember Smoothies as a van thing from the 70s. I had chrome wheels on my 63 Pontiac in 67 but they were regular wheels that were chromed that could take the poverty caps (a new term to me since being on the net) or REAL "Baby Moons". It's difficult for me to fathom but something from 1970 is 40 years old!!! That's all new shit in my antique mind. I never liked anything that was new in the 70s.