[Ron Wood]

Melissa,
Your ability to observe and describe what you see is terrific! There isn't any doubt about the model of your father's Luger, as a couple of our experts have already identified. Just to add our "lingo" to your descriptions here are some terms:
1)"the front half of the pop-up lever" is called the "forward toggle link". The mechanical action of the Luger is called a toggle action and consists of the breech block, the forward toggle link (where the DWM is located) and the rear toggle link where the rear sight is located.
2)"a round flat bumpy button sorta like the mag release" is the magazine release - score one for Melissa.
3)"a long skinny piece on the finger side up just below the big round (? thing?)" The long skinny piece is the "thumb safety" which, in the up position, blocks the grip safety from being depressed. Sort of a "safety safety". The big round things are called "toggle knobs" (a lot of imagination went into that one [img]smile.gif[/img] ) and as you have probably already figured out, these are what you grasp to work the action to load the gun.
4)"the "LOADED" lever that pops up when a cartridge pushes it up" is called the "extractor" since, when the gun is fired, this piece extracts the empty cartridge case from the chamber so that the next round can be loaded. Also, as you have observed, it indicates when a round is in the chamber.

You have a very collectable Luger. There are a few things that makes it difficult for us to estimate the value. First is the overall condition. We would have to see pictures, left, right and top to get an idea of condition. Next is that odd hole in the left grip. Don't know what that is but a picture would help. And last is the "B" scratched probably on what is called the "side plate" or "trigger plate". Scratched on markings don't help the value of collector weapons.

Along with the other guys I will add my Welcome to the Forum! Lugers are a fascinating hobby and I hope you will stay with us and learn more.