I could have sworn that 2 of my girls started sitting at least a week apart, but babies started popping out 2 days from each other. Now I have one left on eggs, and I have no idea what stage hers are at. She nested behind my baby chicken coop, tough to reach the eggs, and even when she gets off the nest, she's a moody broody!
I do understand the hope of getting babies from a particular parent. I lost a hen to a predator and immediately put her last eggs in the incubator. 7 hatched, but none like her. I hope you get some nice babies from your old drake.