I hope this is something you still intend to create, it would be really useful. As well as the physical representations it would be good to collect guys experiences of living with their penises and the various things guys struggle with in terms of the function of their penis. There is still a lot of stigma about things like ED and premature ejaculation that so many guys encounter to some degree at some stage. Im not ashamed to say that I struggle with premature ejaculation but it's not talked about enough, like so many guy things. A book like this could go some way to changing that.
I agree with your opinion, it would be something really interesting. I think many men suffer with the expectations of how our body or our penis is socially supposed it should be. Of course women suffer a lot of pressure on their bodies, especially because of its objectification, which I don't want to minimize. But we also have to deal with some problems...
By the way, I saw your description-drawing at dirtycode.io It looks like a good way to take it with some sense of humour. Greetings.