Do you STILL have a coolant leak? Maybe the clean valve train was from a previously fixed leak. If you had any significant amount of coolant in the oil after the change, it would be sludgy, but not milky (if you have Dexcool). The coolant detected in the oil may have been from some remaining coolant sitting in the valve train or elsewhere. With what I am seeing here, I am strongly suspecting the coolant leak was fixed.
I'd purchase or rent coolant leak tester and pressurize the system with the engine cool. You should not lose any pressure (or very little) overnight.
Seeing how clean that valve train was, I would have expected a big leak. If you are not losing any coolant now, I wouldn't add any coolant fix stuff just now. I'd watch the coolant level carefully after doing the pressure test I mentioned.
