Yes, for a while the nephew was selling some of the NOS stock at very high prices.
The Puma Ducks were a little different because they were clearly marked Puma and in fact were made specifically for DD and then they (DD) also put their name on the razor. Most of the razors they sold while made by others do not have the manufacturer's brand on the razor and were meant to be advertised and sold as DD razors while the Puma's (and there were few others) were meant to be advertised as Puma razors not DD razors.
It's kind of like you go into Sears and buy a Kenmore Refrigerator (and we all know Kenmore doesn't make anything it's just a name like DD) but we know it's made by Whirlpool (probably) of course in that case if you look at the components you'll see the actual manufacturer name somewhere). Then you can go buy an item and it may have the Craftsman brand but it might say "made expressly for Sears by...." which is what the Puma Ducks are.