As not all cans are made the same, either are their bottoms. I have found that some can bottoms nestle well over, or into, the shapes of others, whereas two cans of the same manufacturer do not, as the inner and outer diameters of any contours get in each others' way. That being said, a lid can be fashioned, for an Open Flame Stove, from the base of another soda can whose angles align for nestling. Simply cut the bottom off, around the outer edge of the base, smooth edges, and press/fit together. Some fit better than others, producing loose and tight fits, whereas some don't fit at all. Some experimentation is required to find best/desired results.
See Pictures.