This Primus Combination Furnace is featured in the 1897 Primus Catalog. This is the single burner model. It has a door that can be opened for priming. Fill cap indicate a patent date of July, 4, 1898 Primus logo on tank Primus raised letter on base. View from the top. It is missing the potl. Unfortunately the tank is cracked so the stove is not functional. Ben