Parker, Real or Fake?

[Hail One]

I have recently purchased a pile of old shot guns. In this collection I found a Parker Hammer Shotgun. I have never held one of these before only saw pictures. I am attaching some photos to see if this is indeed a Parker Bros.
It is a 12 ga. with what appears to be shortened barrels. The serial# is 2007 and a "O" stamed under the barrels and on the water table. On top between the barrels it appears to say "Laminated Steel"? There is a type of proof marking on the underside of the barrels. One is an "S" with a star over it and a oval with E L G and a star below it. If anybody has any info on this I would really appreciate it.