I bought a used KSM152PSNK and had it shipped to me. It apparently spent part of it's time upside-down while in transit as a thick brown liquid covered the top and end cover (which arrived dented and the screw sheared off). Is the brown liquid oil? Is it safe to use the mixer? Where can I purchase the screw for the end cover and the attachment knob which arrived cracked? is there a place where can I take the mixer to be tested or serviced in Aurora, Colorado (80014)?