Your gun is from 1949 probably third quarter. I'm guessing 16 ga. because I can't see the rest of the stamping. From the barrel stampings it is an Ideal Grade and for this year should have a roller release within a rectangular shaped metal piece on the forend.
That is the typical fastening system for the "J" spring and the indentation on the loop is to hold the forend on also. The only real way to tell if this wood is original to the gun is to take the metal off and look at the end of the wood where it meets the barrel hook up, the serial number should be stamped in the wood there.
There were different shapes and styles of beavertails.
Take some Oxpho Blue from Brownell's and touch up the tip.
