I did not come across this particular brand as a child, but as a kid I saw other very similar paddleball paddles, and a few years ago looking for a paddleball paddle (and no, not for playing the ball) I got a few Fli-backs from ebay, since they were a prevailing brand there.
There seemed to be two kinds of paddleball paddles, both with ones I remember from the childhood and also among those several Fli-back's I bought. One kind was a thin very flimsy paddles not really suitable for spanking anyone past 5 years of age. Hand spanking would do a more impressive job. The other kind were more solid paddles. If you look on ebay, the first kind of Fli-back paddles are those with a wooden look, and the second are red-painted paddles. Not all red-painted paddles are created quite equal, but they normally are more solid than the flimsy kind.
Flimsy Fli-back kind: https://i.imgur.com/RPEDs7v.jpg
Solid (red) Fli-back kind: https://i.imgur.com/RZLDe9u.jpg
@JohnHill57, what kind was yours?
My first spanking paddle in the childhood used at age 10-11 was in fact quite similar to the red Fli-back kind, except it was not Fli-back but some off-brand paddle and was not red, but just yellow-coated wood (may be plywood). It was however quite similar in size and heft and the wallop it packed.
The closest however I ever later saw to it was not Fli-back, but Cracker Barrel paddle
https://i.imgur.com/Hr5LCHK.jpg
After seeing CB paddle some years ago I really wished to buy it because it was so similar to the paddleball spanking paddle I used to get spanked with as a younger kid, so lots of memories, but when I went online trying to find it, turned out Cracker Barrel stopped to sell it because people were buying it to spank kids, so CB pulled it out of sales.
Another paddleball paddle that was suitable for spankings was "The Paddle Ball King Paddle"
https://usastrojax.com/collections/paddleball/products/paddle-ball-king-paddleball
that suspiciously also went marked "Sold Out". Either it was pulled out of sales for the same reason, or was sold out because it was in great demand, for reasons one may only guess at. Characteristically, one of the top links when looking for "The Paddle Ball King Paddle" in Google, pictures it with the title "Time to spank".
https://gilshulergraphicdesign.com/time-to-spank/