Date unknown, but $5.95 got you a pair of these bad boys including postage east of the Mississippi.
Also, no zip on the address. 5 digit zip was introduced nationwide in the US by 1963. So this may be 50's or at most very early 60's.
This makes sense of a scene from Back to the Future! When Marty was first walking through town upon arriving in 1955, there was a blink-and-you'll-miss-it scene of a girl jumping up and down while wearing her roller skates. At least, that's what I thought they were, and I wondered why she was doing that. But now, I wonder if they were these things?!