If you wish to consider yourself middle class you are welcome to. Being a tailor can put you into several categories. It's a very skilled job - but history shows us that many tailors scraped a living by the trade in the late 19th century and they would have been very much working class. However, they would have been hard workers with decent values. They would have been willing to work day and night to earn a better standard of living for their children and grand-children. Their children and grandchildren may have been a little better off, thus being able to get a little more education and do a little better than their parents. The wealth of the family thus grows and so, generation by generation, they drift towards middle classness by virtue of their income and their education. THE WORKING CLASS VALUES MOVE WITH THEM. This is where the idea that education and hard work are middle class values comes from.
As I have stated, my father was a milkman. He was working class. I am working class. My children, who have had the benefit of well-educated parents and a reasonable income, will be middle-class but the values they inherited from me are working class in their origins.
It's very hard to explain. But if you tell me I am middle-class because my values appear to be middle class you are wrong. If I am living a middle class life because of my education and income put me in that bracket, it is working class values that have got me there and working class values I will be taking with me.