T, the best place to start might be a book called "Understanding Wood Finishing" by Bob Flexner. It is available at major bookstores and on the web booksellers. It lists tests that you can run to determine what kind of finish you have. These are a little long to go into here. It also has a lot of good info on refinishing and color matching. There is a lot of art to this. While the book does center on furniture finishing, the wood and finishing products are basically the same.