I did a little "cut and paste"-experiment with some old pictures.
You can see 6 smurfs, which I am 100% were sold in UK by national before the leadpaint-scandal. So these do not have any yellow dots.
Here you also see the new Smurfette Schleich made around 1977/78.
If you look at the black and white picture from a Nationalshelf when they only had these 10 figurines for sale, don´t you think it looks almost 100% sure that they used the new Smurfette?? Between Drummer and Astro, in front of the black background.
I don´t think Schleich used this Smurfette when they got their old mold back from Bully. But as we all know we can see that Smurfette as a keychain in the Schleichcatalogue from 1979.
They probably only used it a short time in 1978 and that would also explain why it is in the 1979-catalogue with pictures taken in 1978.
Do any of the UK collectors here remember if you bought that Smurfette at the National stations?
At this point the Gardener smurf was sold as a regular smurf called "Gardening", but later it was sold as super gardener smurf. The first 2 supersmurfs sold at National were Racing( Tricycle) and Super smurf-boarder( skateboard). And that was later. The garden playset was sold then though, so you could get the wheelbarrow early and use it with the gardening-smurf.