Hmmm
reading the description, 1969 might be right for that, however all the vintage catalogs I have from that era(68-70) don't show anything like this in Waring, and everything has the permanant blades.
A couple of years ago I bought a Waring Blender new from Williams-Sonoma, The classic beehive, and took it right back after I got it home, namely for the non-removable blades. It would be absolute murder getting chocolate frosting out of that jar!!