Wow. Great photos, per the norm.
I have a pair of 20mm ammo boxes rigged as saddle bags on one of my motorcycles. They are really cool, and air tight so they work really well. One day I went into one of them for a wrench that lives in the box which was sitting on the ground with the lid ajar. I casually reached in and felt the web. It was a black widow about the size of yours. SHIT. It appeared agitated and I jumped back without getting bit. I got a spray can of 'spider death', sprayed the box absolutely full (from a safe distance) and sealed the top for at least a month. You can bet I look carefully now...
I have a couple of those "I didn't die so it was fun" stories too. Adrenaline is my friend.
I've come close to getting bit by different things doing something similar. Good thing it didn't get you.