JTylerBlake,
I'd recommend you use the OSXL (osxlatitude.com) methods at this point. You'll be happier.
Can you currently boot the bootCD in this thread? If so, you can boot your installation that way and use it to create the boot USB the OSXL method needs.
I went through the two different /Extra directories (the one where I got the boot0: error, and the one that works (well, worked until I reinstalled with the OSXL method)):
dhcp-pool160:/ root# diff -rq Extra-leppy Extra-backup
Files Extra-leppy/.32plist and Extra-backup/.32plist differ
Files Extra-leppy/.64plist and Extra-backup/.64plist differ
Files Extra-leppy/com.apple.Boot.plist and Extra-backup/com.apple.Boot.plist differ
... (additional items in /Extra-backup/tmp, and they're all '._' files)...
In that snippet above, Extra-leppy is the copy of the working /Extra; Extra-backup is a copy of the non-working /Extra. Looking at the three differing files:
dhcp-pool160:/ root# diff -u Extra-leppy/.32plist Extra-backup/.32plist
--- Extra-leppy/.32plist 2009-11-22 01:05:26.000000000 -0500
+++ Extra-backup/.32plist 2013-04-02 16:56:52.000000000 -0400
@@ -9,6 +9,6 @@
<key>Legacy Logo</key>
<string>yes</string>
<key>Timeout</key>
- <string>10</string>
+ <string>1</string>
</dict>
</plist>
dhcp-pool160:/ root# diff -u Extra-leppy/.64plist Extra-backup/.64plist
--- Extra-leppy/.64plist 2009-11-22 01:05:11.000000000 -0500
+++ Extra-backup/.64plist 2013-04-02 16:56:52.000000000 -0400
@@ -9,6 +9,6 @@
<key>Legacy Logo</key>
<string>yes</string>
<key>Timeout</key>
- <string>10</string>
+ <string>1</string>
</dict>
</plist>
dhcp-pool160:/ root# diff -u Extra-leppy/com.apple.Boot.plist Extra-backup/com.apple.Boot.plist
--- Extra-leppy/com.apple.Boot.plist 2009-11-22 01:03:14.000000000 -0500
+++ Extra-backup/com.apple.Boot.plist 2013-04-02 16:56:52.000000000 -0400
@@ -9,6 +9,6 @@
<key>Legacy Logo</key>
<string>yes</string>
<key>Timeout</key>
- <string>10</string>
+ <string>1</string>
</dict>
</plist>
dhcp-pool160:/ root#
And that's just the timeout. So the files themselves didn't differ. But the permissions and ownerships aren't checked by 'diff -rq' as above. And the ownership is different, and I'll have to check and see what that tells me.... Will update.
UPDATE:
After a bit of research, it's rather unlikely that what fixed mine will fix yours, and a copy of my /Extra (which was directly from the original bootCD posted way back) won't help you. This is because of what caused my issue in the first place. There is something else going on in your case, I'm afraid, and not having your box in front of me I don't think I can successfully guide you through it. Sorry.