Does it have two holes at the top of the pistol grip for a tang sight mounting?  The Stevens Vernier New Model Pocket or Bicycle Rifles Nos. 40 (flip-up barrel sight) and 40-1/2 (tang sight) had trigger guards.  The minimum barrel length was 10" in the catalog, but there was a warning that any deviation from catalog specification would incur an extra $2.00 charge, so there might have been an opportunity for a specially shortened barrel.

This from Cope, "Stevens Pistols and Pocket Rifles."

Sounds like a New Model Pocket Rifle Model 40  with a shortened or non standard length barrel and missing the stock. I recently got one with a shorter than normal barrel length and am not sure if it was shortened or ordered that way. Stock recently sold on GB for around $200 as I recall. Recently bought a realy nice stock for $250 and ended up buying the rest of the gun for $175 as I recall. It is with John Tayolr at the moment waiting to be relined. Neat toys. Have one in .32 Rimfire that is prety nice and complete with a good bore.

Saw it again today--definitely a 40, the front of the barrel face was uneven on one side, so it might have been cut down a long time ago, but the dovetail for the front sight is so nice, it might have been an attempt to recrown it.

No holes in back strap for the vernier / tang sight, so probably the plain 40.  But, ran a boresnake through the barrel and brought a good bore light--the bore is not good and the nickel frame is more worn than I thought.  So, the gun is maybe 70%.  They were asking $250, but I think this will turn out to be like Slumlords gun--I'll go in at $175--If they'll take it, then I'll restore it with a liner, new nickel and blue.  Of course even then it'll never be original if the wire stock frames were serial numbered to the gun and i can latch on to one someday, but it'd be a nice shooter I think.  Might be a nice single shot to train my 3 year old grandson on in a few years.

Thanks for the help guys!  I'll keep you posted if it follows it's way home to me some day.