Let me tell, now, what I may know about this gun.
There were many, many small custom gun makers in Japan before WW2. Most were very fine and worked their magic much like the makers in Germany and England. There were outsources for specialized parts such as locks, ect.
Most were closed during the war and only the major factories survived.
The new Japanese Gov't ordered many restrictive laws that forced the sporting guns out of shooters hands and into the used racks of the remaining retailers. Most traded many guns for one that they could afford to license. This left a great many fine guns languishing.
The Gov't decided that even though the used guns could not be sold in Japan, it would be allowed that they be exported. They applied a very long number to the water table and off they went for pennies on the dollar.
Your gun, like one of mine (almost twins but for the engraving) looks very much like a Richards. When we took it apart to study, we found that the innards were far better made and finished than the garden variety Richards. That's saying a lot !!!!
Mine is without any marks at all and I have surmised that this is usual with these custom shop guns. It is a fabulous shooter and is often mistaken for a moderately high grade Richards. The plain stock (this is usual for these guns) gives it away as does the lack of a name on the gun.
Some have stated that these were fake copies of Richards. I think NOT. These gun makers simply used a beautiful design and went from there.
I have removed the stock from mine and plan to make it look more in keeping with the fine quality of the rest of the gun.
Mine is shot with Winney AAs or RSTs when I can get them.
I would be cautious about doing anything that lowers the value of your gun. More and more is being found about the custom gun production in pre-war Japan and there is an avid collecting fraternity. Most are on the West Coast and there is where this (one of two I own) came from.I paid $1200 for mine and think that you have a great bargain.After all---It is NOT the name that makes a fine shotgun. Astute men will judge the gun for its self.
Now that I have had time to think, I agree that the Birmingham stamp may be a fake. A dealer trying to assure that it is thought to be a back door Richards.Shame if this be so, for the gun is likely to be a very fine shotgun in its own right.
Hope this is helpful.
Best,
John
