Cuban Mahogany is Swietania mahogani. In antique furniture it's generally known as Santo Domingo Mahogany, and it was most frequently found in the Caribbean.
You can find it in other places as well. It grows in Central America, and even in the U.S. in South Florida. The biggest native stands were in Cuba until the 1950's and 60's. In return for propping up the operation of their government, the Cubans cut and shipped most of it to the Soviet Union (along with sugar cane and cigars).
It's not generally known, but the largest stands of it are now in Indonesia. The Dutch had Caribbean colonies, and being the plantsmen that they are, and recognizing the fabulous qualities of the wood, they transported shiploads of seedlings to their East Indian Colony.
It flourished and is widespread in that country. Not being fools, the Indonesians do not permit it to be cut and sold as lumber, only as finished goods. One possibility to get some fairly cheap is to go to a store that sells Indonesian import furniture. It's not usually very expensive. Look for something that is made up of the proper size woods and salvage it. By the way, expect it to be poorly dried.
The wood is almost as dense as a rosewood, can often have a bit of purpulish tinge, usually has a dark, well marked swirl grain pattern, but is generally much easier to work than rosewood. Although I've handled a lot of the furniture, we've never (yet) built an instrument from it - I would expect it to have a lot of rosewood characteristics.
