Noob mistakes with your car

Just found out about this one over the weekend. Took my bare heads to the machine shop. They bathed them and checked for straightness and cracks, everything was good to go. I brought them home, lapped the valves real good, put them all back together and prettied them up with a coat of paint. I grabbed gaskets from the FelPro kit to get started putting the engine back together and noticed 2 bags of valve seals still in the box. So the valves all came back out again...