Speaking of Jokes (bad ones),
The Sears 6333-4 sold for $250 plus shipping.
Some poor soul paid about twice what you can find them for.
In the ad above he shows a sticker (not on the tube) he says is on the tube.
Probably to cover a scratch he didn't show, or an animal instinct to mark (pee on), his stuff
The former Dave Trott Unitron F700 he's selling now has one too.