Hi, the right spelling is Carvalho. There are a lot of Pimentel and Machado (and some Carvalho) in the small Island of Graciosa, Azores. As thereare only five Freguesias (parishes) in Graciosa,it is not an impossible task to look in the microfilms of the parishes registers to find the persons you look for, once you have an idea of the birth/marriage/death date. A good guess is to start with the Freguezia de São Matheus da Villa da Praia. I have seen these registers and there are hundreds of Pimentel and Machado spreaded in the books. Good luck!