What model J. Stevens do you think this might be?

[Bear_at]

I have a friend that would like for me to help him figure out what model and era pistol this J. Stevens A.T. is. a few interesting features are.
1. the front sight reminds me of a HK troy front sight except it is a complete circle (no open gap at the top)
2. the rear sight has an adjustable (for distance) bar like the rear sight of a 6.5x55 Swedish mauser I use to have.
there is a serial number on both the frame and the barrel assy... that match which is a 5 digit number but no model number that I can find (or even a patent number).
an 8 inch round barrel; It appears steel but may have been blued at one time.

A 2 inch breach, with an octagonal top, elongated sides and rounded bottom. This may have been blued.
The hammer strikes the rim fire pin.
It takes a .22 long rim fire cartridge.
With a push button/screw release on the left side.

I am adding a picture of the dual front and rear sight. T
he front has a single pin surrounded by a large outer ring with a sight notch on top.
The back sight is a pop up style, with a pinhole that lines up with the pin on the front an a v notch above that that lines up with the notch on the round protector at the front.
The back sight is also adjustable for height on a slider.
It also has a screw in the back of the handle and a slide on the bottom of the handle for a removable aluminum (?) stock.

any guesses guys?
I don't know how to post pictures here.. Hope this works.
http://imgur.com/mTE80g8 http://imgur.com/i8pJCrzhttp://imgur.com/vrNKorX http://imgur.com/US2Tscm

[Bear_at]

look above for update

[OkiMarine]

Bear,
What you have is a No. 40 New Model Pocket rifle with a 10" barrel (the 2" octagonal breech is part of it). It is fitted with the optional Stevens "combined" sights. Yes, it should have a wire butt stock that fits on the back of the grip. Made between 1902-1912. the serial number will give a good idea of when it was made and which frame style it is.