The P-51D did not have the hand hydraulic pump.
Here is a video which gets into a cockpit tour of a P-51B. At the 3:35 point, the narrator points out the hand pump and comments that the P-51D did not have one.
https://www.youtube.com/watch?v=zVWtL77f12c
You can also look at page 5 of the P-51D manual
http://www.wwiiaircraftperformance.o...l-5april44.pdf
It notes that "No emergency hydraulic hand pump is provided."