I was disassembling the flush valve in a Toto Supreme toilet to replace the gasket, and one of the heavy nuts that hold the screws to the valve fell off and appears to have gone down the toilet (no pun intended). The other one fell off and stayed right in place, but the other one is nowhere to be found. I'm afraid to do anything else. Could it be stuck on the way into the bowl, or did it go down the drain already? There was a small amount of water that went into the opening when I moved the flush valve, but the tank was pretty much empty save for that small amount of residual water.