If I am correct, and I rarely am, William Riseman was better known as an interior designer, than a fine artist. Don’t get your panties in a fluff, interior designers, you are, indeed artists. It is possible that Mr. Riseman was also an architect. William Riseman, the post office muralist, created two murals in Lynn, Massachusetts. It is not difficult to believe that the man who created the Lynn murals also co-created the mural seen in this Cape Cod Times article. And it is not difficult to imagine that the man who helped create the Cape Cod mural was also into designing movie theaters. But really, all I have is a name, a location (the interior designer worked in Boston, the architect died in Boston, and the post office murals were/are in Massachusetts), and a very rough time frame.
I’ll leave it up to you and other better minds (than mine, of course, not yours; I’d never suggest there existed a better mind than yours).