Is this real??? commercial navy with 8" barrel?
 

Check out what I found on GunBroker.com!
http://www.gunbroker.com/Auction/Vie...Item=550929214

I thought only artillery had the 8 inch.

No such animal. Several German firms made up aftermarket barrels for sale to the US between the wars. The back sight is matched to the pistol, but the balance of the pistol shows no indication of being a Navy.

This pistol not withstanding, were there not some odd barrel and sight combinations found on the so called 1923 commercials? I once owned a 6" barreled 1923 that had a regular 4" style rear sight that appeared all original.

As said above you could get almost any barrel length you wanted after WW1

it was put there by german firms, by Pacifica Arms and who knows else. I wonder how many lugers have been 'corrected' over the years :)