Try Maximo Martinez......
tel 261 0854. He is on Calle El Morro #59, look for Talleres Martinez sign. This is a road off 27 Febrero, Puerto Plata, the main road on which Tropical Supermarket is situated. El Morro is the turning by the Helado Bon Ice Cream Parlour. Max speaks English, but if you are a Spanish speaker you may find it easier to do it in Spanish.