The clapper on such a bell is certainly wrought iron, a commodity which is unavailable these days (today's blacksmiths might claim to work with wrought iron, but in reality their medium is actually mild steel). Welding's a possibility but (as pointed out above) can affect the structure of the clapper & just cause another failure almost immediately.

These days, spheroidal-graphite cast iron can be used as an alternative; the afficianados of bell music will tell you that the sound is inferior (compared to wrought iron), but I can't tell the difference. (Ordinary cast-iron's no good at all)