The "Magda Ding Dong" is as truly as strange as its name. It was manufactured in UK by Harringtons, Walton-on-Thames. Production date is unknown.
Its body is made of cast alloy, the folding wristbrace is bent steel wire with a length of synthetic tubing. Its handle has an ammunition reservoir inside, with a small spring-loaded door at the bottom of the yoke. One of its most unusual features are the one-piece molded bands. They are solid round rubber, tapering down from 3/8" to 1/4" at the pouch. Such one-piece band assemblies are usually found on very cheap toy slingshots because they perform poorly.
One the one hand, it is clearly visible that quite a lot of effort was put into this slingshot: It has a contoured handle, an ammo reservoir and the wristbrace is attached on a swivel that allows it to be folded to the side of the slingshot. I'm sure it was quite an expensive model back in its days.
On the other hand, there are the low-performing one-piece bands, with an attachment that prevents you from installing any other type of bands. I know two owners of this slingshot, and both complain about an uncomfortable wristbrace, low power at high draw weight and poor acuracy. It is a great collector's item, but the Ding Dong will not become your favourite model for shooting.
We can speculate what went wrong - maybe it was designed by a professional toy/household goods designer who had little knowledge about slingshots?