Bluing correct
 

confused about something....I'm given to understand that the bottom of the extension rails on early Lugers were left in the white, but I've seen quite a few pics like this 1900AE that are clearly blued there.....?

Bob, one thing that is learned about lugers and collecting them is that "always" really doesn't apply. I, also, have seen these rails both blued and in the white on otherwise 100% correct 1900 and 1906 DWM lugers. It may have just been a whim whether the worker swabbed the rails with blueing solution or not.

I can't say when the Germans found out rust bluing the friction pieces caused metal spalling..You will not find any such bluing on WW1 guns.

I agree with Jerry, receiver rails should be "in the white". Regards, Norm

Photos can be deceiving. The rails might appear to be blued because of the lighting and contrast, or they may actually be blued. If actually blued, then they are incorrect. Model 1900 Luger interiors are in the white.

nukem556,
I apologize for posting incorrect information. Model 1900 Luger frame interiors are in the white. The receiver rails more often than not do look like the one in your photo. I was a bit uncertain after my previous post so I looked at several of my 1900s and they all have some degree of blue on the rails. Again, my apologies and a nod to drbuster.

I agree with Ron ! All (not altered) 00 I could check here in Switzerland had the under part of receiver blued...

Here most of experts agree about this detail.