Finding a Shooter Navy mind be a problem and then the money you have invested you might NOT want to restore it. Finding a rear sight might be tough too. But, remember not just any 6" barrel will do, you must have the correct height on the front sight to make the back ones work right. Most 6" barrel DONT have enough height on the front sight base because they are set up to use a standard rear toggle fixed sight not the two position Navy rear sight. You can use a standard front sight base but then you have to find a taller front sight. Some of the ones I have seen used have a rifle looking sight which does not look exactly like a Luger front sight but will work. The other guys you mentioned will have more to add. I actually did a shooter Navy for GT once upon a time.
See on GTs shooter it has the shorter sight base but he found a taller front sight, I dont remember, but I think it shot really high. Two different sources of lighting, so the pics look different.
AND Ed Tinker's Navy with Correct front sight block
