Shields, Harper is a regional firm specializing in fuel-related hardware that was founded in 1917, apparently in San Francisco, and is now headquartered in Martinez. Their first Oakland outpost, in the 1930s, was a plant at 1212 Jackson Street (the site of the Alcopark structure) and offices at 361 17th Street. But I remember their small shop at the corner of Broadway and 51st Street, where they moved in 1948 and stayed into this century. It had an opaque frontage, with glass brick windows, and having no idea of what they did I fancied that angels had a secret CIA-type agency there.
Oakland Underfoot 