Maytag took an interesting detour from laundry appliances after WW II with their line of ranges, sourced from a manufacturer in Indiana (?). Also, in an effort to offer a "full line" of appliances, Maytag sourced refrigerators and freezers from Amana. This one for sale is from about 1948-49. The slide-lever controls were indeed unique and only lasted a couple of model years, changing to knob/dials on the rear console by 1950.
The Dutch Oven refers to the oven itself. The floor of the oven is actually a 1/4" porcelain steel plate and the cavity itself was insulated with more than double the usual amount of rock-wool insulation. You could heat the oven and after a specified time, turn off the oven and close the damper effectively trapping the heat inside, continuing to roast/bake for hours "with the gas turned off".
I had a later version with knob-type controls, but it was true, the oven would stay hot for hours. The (huge) downside was that it took 45 minutes to pre-heat the oven. Once hot, the oven baked perfectly even and kept the kitchen nice and warm for hours after cooking was done but it was a ridiculous waste of fuel for small jobs like a quick frozen pizza or Jiffy cornbread. Never have I appreciated having small electric cooking appliances like the winter I had a gas range.