According to Anvils in America page 358, starting around 1907 on Trenton Anvils the Hour Glass Depression on the bottom was replaced by and Oval Depression, which yours has the Oval. Also, around 1909 the Handling Holes are no longer used. So that would possibly put yours around or after that time. I hope that helps. And the value IMO, is .. What is it worth to you. I sure someone out there has a real value assessment for you, but what I am finding it comes down to more than just a dollar per pound price. I have talked to a few blacksmiths who prefer Quieter anvils, which are generally considered lesser quality. Somewhere on this site I read that Vulcan is the vintage Harbor Freight of Anvils. I love my Vulcan, and I just seen one sell for $6.00 a pound. I paid less than $1.00 per pound for mine. I also have a 129# Trenton anvil and paid just shy of $3.00 a pound at an auction. Another Trenton Anvil identical to mine went up for bid before the one won went up for bid. For some reason that 120 to 130# Trenton Sold for $650.00. Happy Metal pounding to you.