Good choice of project.
Blue Collar Bobbers in Utah do kitsets for converting bikes, they have a worldwide market as they cover popular models that are sold in most countries. They are definitely a father/son type proposition, but more of weekend thing, rather than a year long project, if you know what I mean. I guess, like Jon says, there's different levels of DIY: some stuff is bolt on, some requires a bit if drilling or chopping, some requires welding,shaping, metalwork skills etc, (& don't forget cnc) and some bikes are built entirely from scratch (eg. Woody's bike). I guess it depends how far the builder wants to go, how much time he wants to spend, what skillset he has, etc.
I had a good friend when I was in my high school years (I'm 49 now) called Justine Bray, she was in the same church youth group as me, dunno if a relative of yours? They used to live near Lake Pupuke.