I have discovered that the original floor in my 80-yr-old house is wood; it's just like the wood floors in the rest of the house. I would like to expose it and ultimately refinish it. I have two layers of flooring on top of it. One is vinyl, and underneath that is linoleum. My initial efforts have been to simply scrape with a floor scraper (I think that's what you call it--large blade on a long pole). I have been able to remove most but not all of the vinyl and linoleum. There appears to be some kind of dark/black tarry substance as adhesive under the linoleum and on top of the wood. How should I approach finishing the task? Since I have done about 70% of the work myself (not including polishing up the exposed wood), would it be cost efficient for me to hire professionals to remove this stubborn remaining vinyl and linoleum?