Arizona Folks.... What is THIS!!!!

Had this Duster brought up from Az about 4 years ago. Replacing a brake caliper once I came across a "shell" of a tiny scorpion. Now doing the other side UCA bushings, I came across this huge "sack" of something. It's soft but tough. It's probably a little bigger than a golf ball.

Based on this doc, looks like Latrodectus hesperus

http://www.americanarachnology.org/JoA_free/JoA_v41_n2/arac-41-2-176.pdf