Yeah, I was thinking, "What the hell?", when he took out his taxidermist tools and started cleaning Mani's body. It would have been bizarrely funny if he had wanted Mani's stuffed body in his home as a keepsake, or to use as a decoy against the brotherhood.
"No *beep* sh*t lady, do I sound like I'm ordering a pizza?" - John McClane
That would have been bizarre. Almost like when Roy Rogers had his trusted steed Trigger stuffed. Except that this was a movie, and Trigger became an exhibit at Roy's museum in real life.