AIM9,s were definately not fitted to the Nimrod just for show, there is good video of one actually firing one as part of the trials. and we did so many a MISSILE LOADEX,s throughout the 80,s & 90,s it had to be serious.
The best bit about the MOD was the sight, definately Heath & Robinson inspired, but apparently it worked, Two bits of Clear Plastic with a Cross on one, line up the hole with the cross and bobs your uncle, and only fitted to one side (P1), with the Tone fed in through a redundant intercom circuit.
I doubt the Nimrod could keep behind a Herc because of its pretty decent STOL performance but I reckon it could sort out a 707 no problem.
I,ve been in the back of a Nimrod on more than one occasion when its done a bit of dissimilar against Tornado & F-16 and basically as long as its a reasonably slow tight turning affair it usually doesn't fair to badly particularly against a Tornado, F-16 not so good because of its agility. A bit false I know because either of these would just use a longer range weapon and just pick it off.
I reckon it would easily do a 707 but it would be nice to know if any of our Kipper Fleet breathren have been in the situation.