1-3/8"  OAL    Except for the fact that this is a pinfire rather than a rimfire, this is a pretty faithful miniature of the Hopkins & Allen, Xpert Derringer.  The full size Xpert had a  production  run of less than 3000 guns.  It has a fixed barrel,  with a unique flat sided , swing out breech plate (see above right). 

The Xpert is also available in the "Bicycle Rifle" version, with a long barrel, and a screw on metal stock.  OAL with the stock attached is 5"

Either version is available with Rosewood, Ironwood, Ebony, Ivory,  and Mother of Pearl grips. 

Prices:

Xpert Derringer. ........................................... $395
     with Mother of Pearl grips......................... $420
Xpert Bicycle Rifle ....................................... $465
      with Mother of Pearl grips........................ $490