Do you have any mechanical experience? The fluids were probably drained because the head gasket was blown. The engine may be fine, just needing a new head gasket. Drain it all again, oil and antifreeze and pull the head and see how it looks. Get a new gasket and put the head back on noting the torque requirements. I do recommend taking the head to a trusted machine shop and have them check the flatness of the head before re assembling. They can plane a couple thousands if necessary to flatten it.