Here's a photo I took of Tim Lee at the crux of "B...
Description
This route is on the West face of Nancy's Thumb Tower, a 30'-high block on top of the East side of North Fin. Follow the only vertical crack up the right side of the face to the two-bolt chain anchors above. The climbing through the crack is easy, though airy as you glance to your right. The final moves near the bolt are awkward.
Protection
A 3-3.5 Friend and a handful of small to medium nuts or tricams. A quickdraw for the solitary bolt. Chain anchors on top.
If I'm not mistaken, the 5.4 Regular Route ascends Nancy's Thumb on the LEFT side of its west face, exactly opposite Nancy's Crack. You'll find no bolt, and the only pro, if necessary is a placement in a horizontal flake halfway up. The top 10 feet are on ledges in the left facing corner. This really is 5.4, and good for accessing the anchors to toprope Nancy's Crack.
The route described is actually "Ben there dun that", which was put up by Tim Lee, Keith Powell, Mary Jones, and Ben Burnham. I think the bolt-protected move near the top is a solid 5.8.