Okay so I did more research into the whole dealership thing and I came to the same conclusion

There are 2 different images of toothless holding a desert eagle, from what I found, neither of them have high enough res to identify the exact model, manufacturer, and caliber of the deagle,
One I found was toothless from the 3rd movie (in the farewell scene between him and hiccup when all the dragons head toward the hidden world) where he is holding out a desert eagle, I reverse image searched it, and I got a FB post that has the actual IRL photo of the deagle that toothless was “holding”, the text on the side of the main receiver was to blurry to get a caliber or manufacturer.
The second one was the animation, that had a very similar deagle. But it was a 3d model instead of a superimposed PNG from a FB post no one gave a shit about. So it had no text. Plus it wasn’t a rear physical gun so uuhhhh yea no one “manufactured” it technically