Thank you Richard, I always appreciate an update to keep my records current. The machined area under the safety lever on one of my Test Lugers is also appears partially blue and some of my other early Lugers are also darkened in this area. This area is bare metal, so it isn't surprising that if it does not receive the best of care. it is going to oxidize. Your assessment that it hasn't been messed with is most likely correct. I wouldn't be too concerned.

I had picked up your Luger's serial number from Randy Bessler's list in July '04. Mike Reese listed #6196 as being at Springfield Armory Museum in his book on Test Lugers, so your gun is a consecutive number. Nice acquisition, congratulations.