I have written down notes what I found out about the Dupuis smurfs. This is mainly old information but I wanted to check this with you if it seems correct. I will add this to my website later with pictures from the Dupuis and some comics. Since the Dupuis is very very connected to the comics and therefore the comics from these years are important.
For me it is very simple. Dupuis was only intrested in making comics and ONLY was intrested in making figurines to promote there comics. Most likely never sold as toys without the close connection to a comic sold or shown in some way.
If you have pictures of these smurfs I can use together with this information I would be thankful.
I only have a few Dupuis-related smurfs myself so far. 
Here´s the information. Check if it seems correct:
"The first time the smurfs appeared were in the Johan and Pewitt strip, started from 8th of May 1958 in the Spirou magazine. The story “The Flute with six holes” continued in the magazine for several months and in 23rd of October they introduced themselves( pictured).
In 2nd of July 1959 the first smurf story appeared as a “mini-recit” in Spirou magazine. The story was “The black smurfs”( Les Schtroumpfs noirs). And in 10th of December Gargamel appeared in “Le voleur de Schtroumpfs” in the second story about the smurfs also as a mini-recit in the Spirou magazine 1959.
Dupuis was the editor for these comics and that is also why the first smurf figurines made, were made for Dupuis to be used as promotional figurines where these comics were sold. Dupuis did this a lot in the 60s, merchandising of its comics. So Dupuis was not interested in making any toys as said in the book about Peyo, they only had these made to promote their comics. So I believe all smurfs marked Dupuis or made for Dupuis were only used or sold together with the comic in some way.
So Dupuis had these figurines made according to Blue buddies and Kittys cavern.
2” figurines:
Pewitt, 1958
Papa smurf, 1959
Normal smurf, 1959
Angry smurf, 1959
Johan, 1963
6” figurines:
Normal smurf, 1964
Papa smurf, 1965
Angry smurf, 1965
King smurf, 1966
2” keychain figurines:
Papa smurf, 1966
Normal smurf, 1966
Angry smurf, 1966
Prisoner smurf, 1966
Gold smurf, 1966
1-foot figurine:
Normal smurf, 1965
In around 1974/75 the smurfs with the marking Peyo & Ed. Dupuis-union were made. These smurfs seems to have been used mainly in Belgium. So for me I am pretty sure the marking means like this: Peyo( creator of the smurfs) & Ed. Dupuis ( editor of the comics, Editions Dupuis SA in Belgium) had these figurines made together. And most certainly these then were given away or sold together with a comic in some way. This also explains why Peyo asked Dupuis if he wanted to be part of making figurines as toys, and got the answer that they were only interested in making comics. This was during the time Bully made smurf-figurines, according to the Peyo book. And since Naughty is a mold made by Bully in around 1973/74, it goes very well with the fact that these figurines were most likely the last figurines made that Dupuis had anything to do with. The peyo book also tells us that Dupuis was involved in the figurines used as promotional items given away with the Kelloggs cornflakes. This also makes sence since the boxes always had a comicstrip on the back. So most likely these boxes contained Dupuis-smurfs in some way.
I believe these are licenced smurfs but later also used with erased markings unlicensed.
Peyo & Ed. Dupuis-union figurines:
Papa smurf
Drummer
Judge
Vanity
Smurfette
Naughty
"
And the company who made these must have sold or used them themselves unlicensed with blocked markings later?? 
Maureen 
So it is possible they showed them. But I was not born then so I don´t know?? These ads are from a few months before I was born. 
