Replacement parts for Browning A-5 forearm?

Answer

Go to Browning Firearms website, and ask about replacement parts. Or, go to a local gunshow, and ask around the dealers at the show.

Another option is replacing both pieces with a synthetic stock-forearm set from Ramline or others. They are very durable and will not crack, chip or peel ever. They also look terrible compared to wood. This is the cheapest option by far, though, because you'll never have an issue again.