There are a couple of times that the party fires on dinosaurs, but I would assume some of the German rifles were meant to be Mausers. I did not try to examine them closely.
Well since it's a Luger pistol that is last to be fired into the Allosaurus by Bradley before it collapses, it appears as if (their primitive nervous systems nothwithstanding) it fires the fatal shot, so that's what I thought you meant.
My only question was Lisa's nationality. I am not certain if it was ever established.
She's British. When she and Von Schoenvorts are discussing biology at one point she mentions, "German metaphysics," and he replies, "British Imperialism." Anyway I thought her accent would've been a dead giveaway.
EDIT: Speaking of Lisa and Von Schoenvorts, in the book, they know one another because they were engaged to be married (!). And also Von Schoenvorts is a real dick in the book, too, so much so that eventually one of the German crew members bayonets him because he whipped the guy in an earlier scene for accidentally hitting him.
The novel is extremely un-PC about the Germans, but I guess that's a product of when it was written. In the book, there are a lot more survivors of the sinking but the U-bout crew goes around machine-gunning them (!!!). Also in the book, Bradley and his guys are not crew of the ship that the sub sinks but rather the crew of a fishing boat that happens by and picks up Bowen and Lisa, then they board the U-boat (I forget how and why the fishing ship is sunk; I think it rams into the sub and sinks).