Hi forsmf1gradat
Welcome to the forum
Here is a couple of ways that you can tell the difference between a fake #1 Grad and the original.
1. THE MARKINGS
The original #1 Grad will have clear markings where the fake one will have poorer quality and harder to read markings. This is usually hard to tell from an auction picture but youc an always ask the seller to photograph the markings under the feet of the smurf so you can have a closer view.
NOTE: The fake will have the same markings as the original so what the markings are is irrelevant...it's more our clear they are that matters.
2. SEAM LINES
The fake will have a rough seam line (mould line) down the side whereas the original is a lot smoother.
3. TEXT SHEET
The white text sheet saying "#1 Grad" that the smurf is holding is thinner (2mm) with the original...the fake version is considerably thicker (3mm) which is best seen from a head shot looking down.
4. THE FACE
The original version has a wider face whereas the fake's face is narrower.
5. PVC INJECTING HOLES
The original smurfs will have a small circular section usually hidden under the feet that shows where the PVC was injected into to fill out the mould shape. Fakes do not have these.
If you are not experienced with smurfs then it may be hard to identify fakes even with this above knowledge. However if you ever need any help then any of us here would be willing to help you out the best we can to identify whether any smurf is authentic or actually a fake.
If you do not understand any of the above info then just let me know and I will explian a bit more using pics to descibe exactly what I mean.
Hope that helps
Dyar