With historic details as the backdrop of their art-filled home, Nadia and Mark Singleton live in a 1,500-square-foot dwelling in Leicestershire, England. Built in 1919, their space is full of charming fireplaces, unique details, and dark, moody walls.Nadia runs a 3D printing business that produces prototypes for product designers, jewelry designers, artists, and sculptors. Before that, Nadia worked as a scenic artist and prop maker, painting backdrops for theaters around the country. Her hus…