This.
I’ve got three real anvils (two antique {a Peter Wright and a Phoenix}, and one modern English cast steel {Vuaghan-Brooks}), and have used a cheap cast iron Harbor Freight “anvil”. I use quote marks for the cheap one because “shitty no rebound heavy chunk of shit” was too long.
Honestly, a piece of rail isn’t great, but will work for small work. That being said, making friends or bribing the guys at a local metal recycling center or junkyard will do you way better. I’ve known guys to use forklift tines (set on end), large piston sections, etc… All you really need is a semi-hardened piece of heavy steel.
