On Tuesday, June 30, 2020 at 8:19:09 AM UTC-4, wrote:
On Mon, 29 Jun 2020 17:33:32 -0700 (PDT), TimR
wrote:

On Monday, June 29, 2020 at 6:23:24 PM UTC-4, dpb wrote:
On 6/29/2020 7:54 AM, TimR wrote:
...

Quick veer off topic: working on my shed this weekend I had to move
an outlet to replace a stud. I pulled the disconnect lever on the
main subpanel. Put a meter on the outlet, it's still live. Really?
Lights are out, nothing works, but that outlet was hot. So I pulled
the fuse block out, looks exactly like that piece in the OPs photo,
now the circuit was dead. Just goes to show, always check.


So IOW you have two feeds to or in this shed?


One feed, two panel boxes, at first glance it looks like the main one is just a fuse and the smaller one a disconnect, and apparently most of the circuits are that way, but at least one circuit bypasses the smaller panel. I didn't know that until this week.

It sounds like there might have just been that one branch circuit
running out there originally and they added the other panel, not
abandoning the original circuit or you have a split bus panel.
The latter is not unusual with panels that use those pull outs. Some
times they exploited the "6 disconnect" rule and you had to pull all 6
pull outs to kill the panel.

That makes sense. At some point the shed received an addition that doubled its size, and the two boxes are totally different styles. There are two pullout fuse blocks in the box I'm calling the "main," but only one fuse block is in use, the other is upside down.