Vintage John F Stromberg & Co Oakland California Advertising ink blotter. John F. Stromberg & Co. was an insurance and real estate office operating in Oakland, California, during the early-to-mid 20th century (located in buildings like the First National Bank Building and later on Broadway). An advertising paper desk blotter from their firm functions as a vintage collectible ephemera item distributed to clients and local businesses. This blotter was offering insurance for stamp collectors.