I thought this ad was of great use. It states that Trumbull had a pottery division and made Pressed Porcelain Specialities plus advertising their side brand of Sanoware bathroom fixtures. It has the dates of 1920-1929 at the bottom. I assume this was how long they were making products so far since this came from a 1929 electrical magazine. Wish I had a catalog showing all their wares. Great stuff.