FS, does your overflow allow water into the well or is it so high it doesn't?
Mine will fill the well without some sort of plug (I have a sink drain plug in it now but it doesn't seal it very well and still fills albiet slower) and it is pretty high up the side.
On the drain, I just have a plug in it and pull it to drain at the end of the day (or during the day when the overflow fills it
).