Actually mandolin bridges do not come completely shaped, you have to hand sand them to fit the top. they are also machine carved on the top so each string is compensated. This allows the mandolin to play in tune when the bridge is in the correct position. Webber sells mandolins with one piece bridge, but most are two pieces. this allows the bridge to be adjusted much easier. In answer to your question, yes you could make one out of solid wood, but from what I have read, a Cumberland Acoustic mandolin bridge is your best bet. Most important for a good sound is proper fitment of the bridge to the top.