Jack, your anvil is cast, Hay Budden are wrought iron with welded steel face; whole different ball game when it comes to repairs. it's his anvil to do with whatever he wants. My coments concern it's value, nothing more
the description of techinque for welding up anvils given above is right out of the book for weldments on ductile iron and similar to some formulas of cast steel. no big deal. that HB anvil repair will include welding to wrought iron (no small trick due to the silca content) and welding to W1 tool steel face (my concern of drawing the temper on some wonderfully hard tool steel). if this repair was to a large die that couldn't be removed for re heat treat; it would be shot peened to "work harden the weldment to add some life to the repair
when I was a kid, I worked as a helper for a company called WeldMold in Brighton,MI, that repaired stamping dies, forging dies and plastic injection molds. I've seen my share of the good, the bad, and the ugly when it comes to weld repairs in the industrial world.