That's funny. Do you know if the pieces of the pump in the pan came from the mechanical pump that's on there now? Maybe it was the prior owner and he just installed a ne pump and left the pieces in the pan.
If you decide to install a new mechanical pump, don't buy a new one. Find an original pump or a replacement pump made prior to 1995 and rebuild it or have it done. The new mechanical pumps are ALL Chinese garbage right out of the box.