Over at my moms house today, helping her clean out an old storage area under her sink.
As it turns out, my mom used to sell tupperware at tupperware parties when I was a kid in the 70's. I found 3 smaller ones and 1 large one down in the far back, hidden for nearly 30 years, vintage circa 1979!
My SWAT upgrade I'll be working on just went a notch. I read somewhere on here that they used the smaller ribbed bottom attached to the larger lid's flat piece. Gotta find that thread. Anyhow thought I would share!