Can You Place a Metal Roofing Over a Shingle Roof?

http://imfl.sci.pfu.edu.ru/forum/index.php?action=profile;area=summary;u=751797

We have a 1890's residence with a combination Mansard design roof covering and also typical sloped roof covering. We are going with a mix roofing (Malarkey Windsor Roofing Shingles on Mansard as well as standing