If of interest there is a book called "Uderzo croqué par ses amis" ("Uderzo Sketched by his Friends") published in 1996. This contains a number of short comic strips drawn by a number of artists, including several leading ones.
The main theme of the strips are that Uderzo gets into a number of odd, sometimes surreal situations, most of them involving Asterix and other creations. One strip, for example, has Chief Vitalstatistix going to Lutetia and commissioning artist Uderzorix to paint a portrait of Asterix. They travel to the village in a chariot with Ferrari symbols on it.
Two of the best (one by Jean-Marc Stalner, the other by Franz Drappier) depict the characters in a realistic style, which can be seen as pastiche.
Even the map of Gaul at the beginning of the book is rewritten to state that "All Gaul is occupied by the mangas... All? No! A village of diehard big-noses still holds out against the invaders", with the village surrounded by Japanese samurai and robots.
It can be found here at Amazon France
Personally, my only criticism of it is that Goscinny is hardly mentioned. He is only seen in a rather obscure profile in one strip and mentioned by the initials R.G. in another. It may be a book dedicated to Uderzo, but it also appears to give him all the credit.