There are two different camps on repairing anvils....some say work around the damage, and some say weld them up.
When welding them up, if I recall correctly, they use a rod that absorbs impact better than regular rod. They build them up with Stoody 2110 and then finish the last 1/8 inch with 1105. I think these have an impact resistant quality due to high manganese and/or nickle. Been a while since I studied on face repair....I lucked into my anvils without substantial damage.
That big anvil was probably one of the Mexican cast knock-offs that make their way into the country. I've heard over the years of several being sold as "antique".