Header fail is because unself from ebootfix and friends cannot handle npdrm i think.
You can see here for more details. Except, i cannot find the package to download anymore.
unself2 and unself3 are included in ps3tools these days. Unsure about the npdrm keys.
I have setup ebootfix with unself3.exe renamed to unself.exe, and i keep getting the same header errrors like you guys.
SCEtool will unpack those eboots for me just fine though. So why not use that instead of the (older) f0f tools? Didn't test it with sprx yet myself..