Nutloose,
To answer your query re wingtips, they were fitted mostly 1989 onwards to cabs that had undergone the Avionics upgrade - ASR1012, Mod 1736. The short tips reduced wing-loading, particularly whilst pulling 6G at 30 feet, with the throttle levers through the panel... allegedly... and therefore extended the fatigue life. Note that the cabs did not return from Avionics upgrade with the shorter tips; they were fitted later, e.g., XV161 - 12 Sqn "AF" returned to Lossie/12 late '87 - early '88, but was not fitted with the short tips until sometime in '89.
You may find some more info on which cabs were modded, and when, here:
Contents Page
Looks like a good kit in the offing - any idea on the role fits likely to be offered, e.g., TV Martel + Data Link Pod, TVAT, etc?