Well, I'm an idiot. But we all know this already.
So I took my own advice and bought two of the Silnote Audio Poseidon GL Reference power cables. They arrived shortly, straight from the manufacturer. Really nice quality, of course, and a great company to deal with. (And I'd recommend getting the GL Reference cables over the next week or two while they're still on sale.)
Now, I go to stretch one out and give it a trial fit from my phono stage near the top of the rack, to the power conditioner.
Too short.
But things are dusty, so I break down the rack. Maybe I'll move it out or rotate it so I can put the power conditioner behind the rack. I unplug one of my PS AC-3s from the Oppo (which is being replaced shortly), stretch it out...waitaminute, it's 1.5m! Since when did I buy that?? So, crisis averted. I can use that AC-3 from my top shelf. I kind of wanted to use the Silnote on the preamp and phono stage (same manufacturer, same basic purpose), but I guess that's not happening now. Not a huge deal either--the AC-3s are no slouch.
Finally get the last level of the rack off, and I'm down to the power amp and the base of the rack. I undo the power cable from the wall...and I'm pulling out an awful lot of power cable from underneath the rack. Guess what? That AC-3 was 2m! I certainly don't remember buying that either!
Now I'm back to digging through emails to see if I really did get longer cables than ordered, or if I'm just that forgetful...
Things are sounding a little strange, but my room is still in disarray and the light tinnitus I have is acting up today.
The spare AC-3 I have now is reserved for when I can get together a parts order and buy a good Furutech IEC socket for the power amp, then find someone who can do a clean cut on the chassis for me so I can install it. The frayed jacket on the power amp's cord is a little worrying still. (Not bare, but still...)