Chainsaw wrote:

Not to belabor it, Morgan, but I suppose under your intepretation, skeletons (and automatons) wouldn't be able to "see" those under Invisibility effects either, correct? I have historically taken more of a supernatural "sense-the-living" approach, which would have ignored Invisibility.

They would be treated as any other monster.  Necromancers get Invisibility to Undead as a first level spell that is the same as Invisibility (I think) but just for undead.  Given the spell is the same generally I would assume the undead would be fooled by the regular Invisibility spell as well as Invisibility to Undead.  I think the description of the monster would have to say "see invisible" for me to nix the spell.  
 

Blackadder23 wrote:

As far as iron automatons go, they are described as "immune to sorcery, except lightning". Bronze, clay, and stone automatons have similar restrictions, and flesh automatons are "immune to charm, hold, sleep, and other mind-affecting magic". So that would seem to rule out hypnotic pattern against any automaton in the RAW (which of course any DM can and should ignore if they wish).

Tombs of the Blind Dead is exactly what I was thinking about with the "unseeing skeletons" bit.

Yup!  I would rule that way since its specifically stated.  The Blind Dead movies were cheesy but innovative for the time.  I own and love them!