In 95 to 98% condition these guns are valued $300 to $350. In mint condition around $400
It is most likely a model 1900. They where only made from 1900-1910.
I have one with serial #343641 that was made around 1905.
You can find them on Remington's web site.
Value is hard to determine without picture or more info. Most bids start around $400.
Couldn't find that particular model listed but most Stevens pumps go for between $100 and $200 Made from 1936-1943, with a value of $100 or less. firstname.lastname@example.org
I have the same model as you. I inherited from my great grandpa, and to the point of my understanding it was distrubuted around the 1930's.
If it is really 100% like new, maybe $100.