Hi Autoloader,
You have your right and left mixed up, unless the gun is pointing at you.

The only thing I can think of for this modification is it's easier to accuate the safety with your thumb. You don't have to reach so far back. This is very simular to the (Baby Luger). But of course it didn't have the thumb safety lever.
Also it looks like it has a stock lug to me.
Mike C.