Stradivarius violin

Some time ago, I was over at a friends home they had an need to open the china cabinet which was locked. Since they had lost the key they asked me if I knew of any way of opening the cabinet with out breaking the glass. I studied the cabinet and came up with a solution. Upon opening the cabinet they wanted to reward me. I declined. Somehow the conversation came around to violins. Char excused herself and went up in the attic. Several minutes later she returned with a small case, a violin case. She wanted to give me the  violin for opening the china cabinet. I opened the case and took out the violin and a bow. The horsehair needed to be replaced but there was enough on the bow to have me play the instrument. I have never played a violin but I did know when it was out of tune. I made some adjustments to the strings and it sounded better. After I tired of playing I was about to put the violin away when I noticed the makers name on the inside, Stradivarius. My eyes grew big. I wondered if it was original, but didn't feel comfortable asking. I knew my friends family were very well off financially. They were also Dutch. I believe the violin was a true Stradivarius. I declined the offer to accept the violin as a gift citing it was a pleasure.