anvil

n it . can't find out what kind of anvil it is.
That's likely a weight marking, indicating that it weighs about 150 pounds, or did when it was originally made. It doesn't tell us much about who mad e it.
Without any other marking it's hard to say what brand it might be. If you' re able to tell us more about the pattern and features of the anvil (Englis h pattern, double horn, does it have an upsetting block, etc) the construct ion method (cast vs forged), if it looks like the face is welded on or if i t is solid, and some dimensions, then an anvil genius might be able to narr ow it down for you.
That said, I am not an anvil genius, and I'm not sure too many folks are st ill using this group. You might have better luck on the forums at Iforgeir on.com , , or, if you are on facebook, the "American Anvi ls" Facebook group

Best of luck to you!