I own a 12 bore with 2 1/2" chambers and ejectors. I am told it was manufactured around 1900 (serial # K 14xx). I bought it because it has fabulous balance, weighs in around 6 lb 4 oz and has stock dimensions I need. For me that is a nice weight, although the balance/fit were deciding factors.
I checked out the web site for T. Stensby & Co and it is not very informative. I sent them several e-mails trying to confirm the date of manufacture and original configuration, but I never heard back. A fairly knowledgeable friend thinks it is a Birmingham gun labled T. Stensby. Another source told me they made their own at turn of the century.
I have used it extensively for pheasant, grouse, quail and woodcock. I own 6 other shotguns and this is my favorite.
You may want to employ the logic my grouse hunting partner uses. "I dont know how many shotguns I own, but I know I need one more"