To help and not help a bit more.
You can tell approx age by the type of magazines, i.e. wood bottoms were used until about the mid-1920's, then alumnimum was used, then later the black plastic.
You can get a VERY rough guess by serial number, as many years used the same serial number and suffix.
There should be a web page that shows the many types.
If folks send me pictures of as many types as they have, I will collate and make a webpage on this.
weimar_lugers@comcast.net
Ed