Sigh. I must be a bit dense (or at least unfamiliar with Visual Studio). Or maybe I just don't follow instructions well. But, in case anybody else finds themselves in this situation, here is the explanation.
I tried to add the reference to MapWinGIS by clicking on the Visual Studio "Project" and selecting "Add Reference". I then selected the COM tab and checked off the MapWinGIS selection. That makes MapWinGIS show up in the references, but the control doesn't show up in the toolbox.
Instead (or in addition to the method described above), right click on the VS Toolbox and click on "Choose Items". Then, click on the COM tab in the window that appears and select that you want the MapWinGIS control to display. This makes the control appear.
I tried to add the reference to MapWinGIS by clicking on the Visual Studio "Project" and selecting "Add Reference". I then selected the COM tab and checked off the MapWinGIS selection. That makes MapWinGIS show up in the references, but the control doesn't show up in the toolbox.
Instead (or in addition to the method described above), right click on the VS Toolbox and click on "Choose Items". Then, click on the COM tab in the window that appears and select that you want the MapWinGIS control to display. This makes the control appear.