Old Parker identification

[Clifton Stripling]

I just got this Parker 12Ga. Its in rough shape but appears to be older than any info I can find. The only numbers on it are 13 under the barrel end and the number 23 on the forestock tang.
The letters WM on the barrel end and Laminated on the barrel rib.
there is lots of engraving, with a pair of geese on either side of the receiver back, with Parker towards the front.
On the underside of the barrels is OB on one and GB on the other, it could be both the same but that is my best guess.
There are several cross sword type marks and 12 G in a diamond there also.
The buttstock end is hard rubber and there is a small brass oval on the bottom of the stock.
There are no other marks.
Right hammer has been replaced.