Lens building

[DoylerCrewless]

I'm interested in building my own lens for my phone instead of buying one premade. I kind of want it to be a little more intimate than gluing a lens to a case and slipping my phone into it. Although with that said, would cannibalizing a camera from goodwill even be worth the effort? I'm not talking about ruining a piece of history but more along the lines of repurposing a camera that would be looked over by most photographers. I'm not asking anything about difficulty level. It's not about saving money. Any input helps