Back in the early 80's, Watto, (the late) Terry Truman and Alison (?) were digging in the choke but were following the water.
I went with them on one trip. That was enough! The fresh scratch marks on the transit sized boulders that had moved since their previous session didn't endear the place to me! It's one of those sites that reminds you of an ant in a bowl of sugar cubes!
The dig crapped out a fair way in from memory. Now that capping is an option it could be worth re-appraising the choke, but I'd take a change of shreds if I were you!