N8VEM project with my son?

Hi, I'm about to embark on building a single board computer (an N8VEM) as a project with my 15yo son. My son is a typical gamer kid who spends most of his waking moments either in front of a computer playing WOW, or reading SF and fantasy. I'm trying to find something a bit more positive about technology for him to enjoy. The operative word is enjoy. Anyway, he's agreed to give it a shot, and I'm thinking through how to make this a great experience for him. I've got a fair amount of background (BSEE and MSCS), and understand the technology, at least theoretically, from bare silicon to flip flops, to computer block diagrams. I'm reasonably well versed in Z80 assembly language programming and the CP/M operating system, which is what the N8VEM runs. I've got the equipment (electronics soldering station, good DMM, logic probe, bench power supply, etc) and have access to an OScope if I need one. And I actually sort of remember how to use them :) My question for you folks is: At what level, and in what order should I try to teach some theory to my son? Should I do some background before we start soldering sockets and ICs to boards and wiring things up, or just jump right in to building? I've been thinking jump in and fill in the theory as I can as we go along. In the end we should have something that looks like an Altair with more modern HW: solid state drives, and maybe IDE, but still has a front panel and which runs traditional CP/M 2.2. I have lots of old software to run there, languages, editors, games, etc. Have any of you tried something like this with your children? Experiences and wisdom gratefully accepted! Cheers, Tom