Are you sure he is not locked up in the house somewhere?
Indoor cats are very scared if they get outside and rarely will wonder far. Some are even too afraid to come out during the day when their owners call them. Best time to look is at night and very early morning. Take a flashlight to shine in bushes and under structures, so you can see the reflection of a cat's eyes.
If you can leave something of his and an worn shirt of the person who was closest to Eskie in your back yard (even some of his kitty litter). Check through out the night.
Ask your neighbours to check under their decks and in their sheds. My parents had a neighbour's indoor only cat under their deck for 5 days. It came out just before sunrise and was peering into my parents basement window, then ran back under their deck.
Cat maid to:
Jasper, male Ragdoll ?? (approx 10 yrs)
Rose semi feral, a cpietra rescue, female tabby (approx 7 yrs)
Sweet Pea RIP (2004?-2014)
Puddles RIP (1996-2014)
Snowball RIP (1991-2005)
In a cat's eye, all things belong to cats.-English Proverb
“While we are free to choose our actions, we are not free to choose the consequences of our actions.” Stephen R. Covey