Frank Major Tobin bought Clarance Wallan's shotgin patent and set up shop in Norwich,CT in 1904 until 1909 then moved to Canada(1910-1916) as Natty said.
A total of about 12,000 Tobins were produced.
References: The Double Gun Journal Vol.5 Issue 1 & Vol.8 Issue 1.
The Gun Report Vol.39(May '94) & Vol.
The Canadian Journal Of Arms Collecting Vol.34 #3
The value of your gun depends on the grade,gauge,features and,most of all, condition. Tobin guns are seldom encountered at high end gun auctions. I have seen them go for as little as $300 and as much as $1395.