I have a Tech priest in my group and he wants to create a servitor from scratch and we cannot for the life of us figure out where the heck the rules are for creating them. Are we just blind deaf and dumb or is there something we are missing

If you wanted to build a Servitor from scratch I'd just use the rules for creating a cyber-creature familiar from the Inquisitor's handbook but make the base "animal" one of the NPC's from the DH core book. I would recommend that you choose between the Citizen, Dreg or Heavy.

Keep in mind that this isn't a perfect fit. But it will do the job.