First, regarding the brake adjustment routine, Mark Symonds did a very nice job of describing the procedure. I have always done it a bit differently, but one of the benefits of writing is that you get the chance to describe your process to yourself first and you often learn something about your procedure through explaining that process to yourself.
Second, regarding improving the Vincent brakes, the problem is truly systemic. Yes, you can get every adjustment a little better, but before opting for a different brake, I would urge you to consider a new steering stem. The use of an improved brake is strongly counteracted by the stock steering stem, which can make large improvements in the brake quite dangerous. In general, adjusting the brakes correctly will not cause serious problems, but changing to discs or four leading shoes can lead to bad behavior.
Finally, the stock shoes and linings are inadequate. Good alternatives are available. There are many more minor issues like poor cables, weak brake plates and improper levers. Most owners focus on these last three to the exclusion of all others for the reason that they have received lots of attention over the years.
I understand that you want a manageable winter project and I think that can be done. Some of these improvements are only necessary at competition levels and not necessarily required for everyday street work, even if they are improvements. Many owners have found that ribbed drums and Lightning plates have improved the front brake, as well. It might be useful to list all the options that exist and decide which of them can be accomplished easily and which ones are too difficult or too expensive.
David
