Thanks guys. I'll be starting to gather more knowledge on these for the next purchase now.

As a side though. What could be the typical cause or reason for the spotty/uneven finish on the 9mm luger?

Also, the top doesn't stay racked down when the magazine is out, but it does with an empty magazine in. Is that typical?

-Don

the top doesn't stay racked down when the magazine is out, but it does with an empty magazine in

Don, the empty magazine follower button pushes up on the hold open, locking the toggle back after the last round is fired.

Spotty finish is usually environmental factors, especially a lack of diligence during periods of storage, generally a lack of oil on blued surfaces. But during certain years the bluing appeared thin in spots or on certain parts, and some parts appeared to be sort of a plum color. Hard to tell how wartime effected manufacturing processes.
Add to the mix heavy use in terrible conditions (war), chemicals, blood, etc, and it is amazing that we see so many in great shape.
dju