Observations on some of your requests:

3. Many, if not all, aircraft that had differential brakes already have them. Get differential brakes by swinging rudder.

5. The two aircraft you mentioned, the B-17 and P-47, only have the two stages they already have, one turbo and one internal. Maybe you're requesting more direct turbo control? That would, maybe, give slightly better economy but not more power, I wouldn't think.

8. Hydraulic system failure gear drop. The only possibility for this might be the very early P-51D which did not have a mechanical uplock originally but had them retrofitted*. Most hydraulically operated landing gear and flaps had mechanical uplocks so the hydraulic system could be placed in neutral between uses. *http://p51h.home.comcast.net/~p51h/sig/TO/01-60JE-9.pdf



PS For those who haven't seen it yet this site is awesome for all things Mustang (technical): http://p51h.home.comcast.net/~p51h/sig/sig.htm