Bryan,
Your Luger is commonly called a "1920 Commercial". It is more appropriately called an Alphabet Commercial, because of the script letter (yours appears to be an m) under the number on the front of the frame. This is properly part of the serial number, so yours would actually be 989m. These guns were manufactured by the thousands by the DWM manufacturing company between the two World Wars.
It is very important that Lugers be matching and in good shape to retain their maximum value. You can examine pictures elsewhere in these Forums to see examples of Lugers in prime shape. It looks like the takedown lever on your gun has been damaged andrepaired, and does not number-match the rest of the gun.
At the Reno gun show this last weekend quite a few Alphabet Commercials were seen for sale on exhibitors' tables commonly priced at about $850. One there was tremendously overpriced at $1,100; there was one example in very poor shape with the price of $450. I could not interest any dealers in my own alphabet Commercial, in about %93 (very excellent) condition, for as much as $450.
I have no doubt that your Luger is a very excellent shooting gun, they are inherently extremely accurate and a lot of fun to shoot.
--Dwight
