i've not done this quest, but the faction guide @
http://wiki.project1999.com/Faction - would suggest that Amiable is 400 points for the rank... so this might suggest you're getting somewhere between 1-3 points per turn in if you haven't progressed ranks to Kindly.
Would also suggest this is a very slow way of factioning. Knights of Truth is easiest by just landing a hit on to Lucan, that will give +750 in 1 shot or so.