Well , I have 2 peter wrights,124# and 180#, the 124 is the primary anvil in the shop as it is in the best condition,the other I use for its mass.
Newbie anvil,I dont want to brag about luck but my brother hauls scrap and he stopped by on Fri to let me look thru his load. A wonderful load of heavy melt. The most manageable pieces I could toss out of the trailer were 4x8x23 inch. One will be used as an upsetting block, and the other I will play with. I am thinking that I will try to make an anvil similar to the Brazel brothers,that I have seen pictures of. At 208 lbs it will make a nice anvil. Gotta love living near a steel town.
Just a note on mass being the big thing for an effective anvil, we have to remember that a large anvil can be a good heat sink when working lighter material,sucks the heat right out of hot iron in the morning.