100-300 USD
You will need to start by contacting Mauser
100-400 USD
Stevens was in business from 1864-1950. They did not have a "pocket pistol" model, but DID make a "pocket rifle" model from 1869-1916. Am aware of no specific production data based on serial numbers.
@ 1866.
It depends on exactly which model it is. I have a model 1934 Mauser 7.65 pocket pistol that is worth (according to "the book") about $500, however, there are some rare models that are worth much more, some well over $1000, if I remember correctly.
It was made in 1864.
Old catalogs
made about 1918
What is the value of 1903 colt pocket pistol.32 calibre?
If it is a Colt Vest Pocket model, 1921.
Small vest pocket pistol
Between 1921 and 1982, MAB made several pistol models in .25: model A vest pocket pistol model B vest pocket pistol model E pocket pistol model GZ pocket pistol (actually made under license by Spanish gunmaker Echasa, as MAB Espanola) The value will depend on which model it is, which version of that model, and condition. Since 2010, the range for the above pistols is about $50 - $300.