That might actually be a good starting point! Compare the hal files and see how we can implement them into Vista's hal. Build 6519 might also be the first 7 build to accept pure 7 drivers, at least I think so as I tried a 7 build earlier than that, and from what I tested, it appeared to not accept the 7 drivers (and this was either on a 2015 HP or a 2019 Acer, I can't remember).