[Updated information with photo]
At a beach cottage, I ran into a gas-fired, direct-vented heater made by a now defunct company named Locke Stove Company in Kansas City. They call it a Moores heater, model 1450RMA. Best guess is that it is from no later than the early 70s, likely farther back. It is about the size of an average radiator but it is a miniature furnace with a pilot and everything. Serial number was hard to read but could have been 1971.
Thanks in advance.