I wanted to thank the OP - my handbrake warning light just suddenly stayed on, and this write up made it very easy to get everything apart. Although his warnings weren't quite enough to stop me fumbling multiple things into the abyss under the handbrake console, heh.
Turns out my contact bow was intact but entirely the wrong shape; took finding a clear picture of a new one (from an old For Sale ad on Early 911S) to figure out what it should look like.
Note the bow is a straight line after the rivet holes, followed by very nearly a right angle::
Mine was like 45 degrees after the area supported by the handbrake lever - guess 250,000+ miles on the tub had taken a toll, and it'd just deformed slowly over time until it made contact with the brake off... Bent it gently with needle-nose pliers until it looked like a new one and it Just Worked when bolted together again... I'm guessing this was expected - the "switch" was in the very lowest adjustment position when dismantled, and I put it back right at the top.
Gotta love a $0 fix...
