It's easier to get away with a frame that's a bit large than one that's a bit small. okay +/- 2cm you can get away with, but over 6? Nope.

Even if you can find a seat post and stem that can compensate, you'd be turning a sweet race bike into a clown bike. I hear what you say about re-imagining bicycles and building them up in different ways, and I enjoy that also. This is different though. Even I could see a Hetchin's set up the way you have and think "cool", but you need something at least 58cm to have a hope of pulling this off, and even that's stretching it, imo.