Hi Mike, WELCOME!!!
Nice looking 1939 Code 42. It's difficult to answer your finish questions. The ejector appears to be correct. Lugers around this time period had various parts that have turned "plum" colored, so don't be concerned about this one.
The "fxo" marking on the magazine is a German Ordnance Code for Haenel, the magazine maker. It's the same idea as the Code "42" on your pistol toggle is the Ordnance Code for Mauser, the Luger manufacturer. Having said that, it is NOT the proper magazine for your pistol and it appears to have been altered by changing the number. The correct magazine for your pistol should have an eagle over 63 Inspection (Waffenamt) Mark stamped on the aluminum bottom.
Hope this helps a little!