Gaylord-Wilshire and Moxie, interestingly, do you notice in this map, ca.1914, there is very little development in the Valley but you can see the basic route of Sherman Way taking shape, originating in Lankershim making a ninety degree turn north at Van Nuys and another ninety degree turn to run west and end in Owensmouth. And here's a couple of interesting things, first the east/west section is called Van Nuys Blvd(!) on this map. I've never heard of that before. Also if you look closely you can see that 'Sherman Way' north of the Owensmouth cut-off is called N. Sherman Way, hence G-W, your address for the piano manufacturer was exactly right being 6001 S. Sherman Way. Great stuff.