Definitely an R gun. Looks to be R15 or higher-I would need to see a photo of the flats of the barrels to tell for sure on this gun. Better than average quality on the engraving, for a pre Bruchet era gun.
The emblem in the stock is what remains of the original butt plate, that someone thought would look good screwed into the stock, after they removed it to put a recoil pad on.
Not exactly best grade work on either modification. Still, if it works, so be it.

Best,
Ted