Is That What That Rule Says? - Morale

As I continue to read through the rulebook in preparation for my gaming group's next big game day, I've found that re-reading the rules with actual game play under my belt has given me a far more concrete understanding of them.  Far different from the abstract understanding I had from reading the rules before I played a game.  But I've also found rules I've messed up, normally just messing them up in my memory as we've played.

Today's rule is Taking Morale Checks, hit the jump to see what kind of idiot I am this time.


Reminder, the bold emphasis is by me, any italics are directly from the book.
 
What the rule says:

Warhammer 40K Rulebook p.44
A) CasualtiesA unit losing 25% or more of its models during a single phase must pass a Morale check at the end of that phase or else will fall back.
C) Losing an Assault
Units that lose a close combat...must pass a Morale check to hold their ground.
Units taking this Morale Check suffer a -1 Ld modifier for each wound their side has lost combat by.

How I've messed it up:  I've been modifying Morale Checks caused by losing 25% casualties.  Specifically I've been adjusting the Ld score down 1 for each model lost.  Not only that, but I was modifying Close Combat Morale Checks down 1 for each model lost, not the difference in wounds that I lost that assault by.

How this has affected my games:  Obviously this has really put a crimp on morale checks in the shooting phase.  For the Orks that I play not so much early on for my Boyz, but smaller units like Nobz and Lootas can really be affected.  Not only that, but we've really sort of made it worse to lose Close Combat in most circumstances by modifying for ALL models lost, not just the difference in wounds.

How I should have played it:  First off, nowhere in the Casualties section does it specify modifying the Ld at all.  So I need to stop doing that.  As for Losing and Assault, well we just need to do better at modifying for just the difference in wounds that the loser lost that assault by.

So, am I right in how I'm interpreting the rule after re-reading it?  I'm pretty sure this is the case, but I just want to make sure.  I've checked the FAQ and nothing is listed there (not that I expected there to be), but please let me know if I'm totally screwing something up.