What is weird, is that I can't find detailed information (illustrations and photos) of the front hull maintenance hatches, and I got several good books on the Panzer III including "The Spielberger German Armor & Military Vehicles Volume 3 - Panzer III and its Variants".
What I can gather from the text information, photos, illustrations, and drawings in these books that I have, it does look like there were hatches you pictured above, but in the production. Most being the split hatch and the one piece hatch with visible hinges. But I can't find are photos or other information of hatches with four holes/dimples as shown in the example below. I will keep searching.