G,
I think your 318 is a better quality rep than that particular 111. I am by no means a Panerai guru, but the font on the lettering looks off and the L SWISS L at the bottom is not that good. Since there are no movement pics I can't judge, but with the open caseback Pams the movements need to match up with the series; E Series watch needs an E Series movement...
And yes, it is very similar to your 318, so unless you are getting an awesome deal, or absolutely have to have this one I suggest you stick with your 318.
Please don't take this as a slam to the person wanting to trade - the 111 watch is nice, but IMO it's not as accurate as the current 005 and 318.