You have a Fisher anvil, made in Trenton, NJ, in 1914. The 10 on the leg indicates a 100 lb anvil. The 50, 100 and 150 lb anvils where the most common sizes Fisher made.
Value: worth whatever someone will pay for it.
Yours in in decent condition, although not mint. I would only clean it with a wire wheel, no grinding. You will learn to work around any chips. The horn nicks will not be a problem. Really no need to grind away any of the hard plate unless you want to put it on display and never use it. If you do insist on "cleaning up the nicks" use only a flap type sanding disc on a small offhand grinder lightly. Fisher anvils were typically painted black on the base area, not the working surfaces. Of course, it is yours. Do whatever you want with it. And enjoy working with a great anvil.