Rick
Just followed your post to do the throttle return spring modification. Excellent posting, but (isn't there always a "but"?) a couple of points I found that might help, only because you've gone to such detail that an innocent (like me) can find unexpected unknowns.
In raising the tank, slacken the pivot bolt at the back:
You gloss over the removal of the "lump" (with three vacuum[?] tubes and an electrical connection). Note the white plastic tie holding its wires to the tank wiring, needs cutting and replacing when re-installing.:
Here the "lump" is just taken out of its wire holder:
The only other comments are I had to get a third hand (sons do have their uses sometimes) to hold the throttle open the quarter turn necessary to get to the spring, and as I couldn't find anything to grip the spring to pull it off the hook, I used two flat-bladed screwdrivers, one to push the spring tang forwards until it was just clear of the hook, the other to push it sideways off the hook, in the end very easy.
The result? Much improved throttle control, so thanks for the great write-up that gave me the confidence to make this adjustment.
I'm off on a tour of Scotland in three weeks, should ease that wrist ache!
FWIW, I took a few photos of my progress (I do this so I know how to put things back!), they can be viewed
here.