You're welcome. Please report back and let us know what you come up with.
Yeah that's a big ass thread. I tried to read all of it once, somewhere past the middle of the thread you'll find a summary that I made of some of the general points..then I gave up. Also look up fassl's original DSDT Patcher release thread over there, it's a gold mine as well.
Finally, when you tried patching the SMBIOS values, e.g. using smbios.plist, did you try to change more than the product name? I tried changing "SMmanufacter" and similar texts, but instead System Profiler keeps showing only "Mac" as the Model Name. Is that normal?
All I can think of is either there are some strings missing from your plist or you have another SMBIOS injector still present in your extensions folder causing a conflict. Make sure you have vanilla AppleSMBIOS.kext and no other kext with SMBIOS in its name in the extensions folder.
I had to use OSX86Tools to reset the 'about this mac' info and log out and in a few times before it showed up correctly there too. You can also do it manually, by editing SPPlatformreporter something or other. System Profiler showed the right information from the get go.
Here's my current smbios.plist spoofing a 2009 model iMac 9,1 with all the stuff I could find up until now.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>SMbiosvendor</key>
<string>Apple Inc.</string>
<key>SMbiosversion</key>
<string>IM91.88Z.008D.B08.0904271717</string>
<key>SMmanufacter</key>
<string>Apple Inc.</string>
<key>SMproductname</key>
<string>iMac9,1</string>
<key>SMsystemversion</key>
<string>1.0</string>
<key>SMserial</key>
<string>XXXXXXXXXXX</string>
<key>SMfamily</key>
<string>Mac</string>
<key>SMboardmanufacter</key>
<string>Apple Inc.</string>
<key>SMboardproduct</key>
<string>Mac-F2218FA9</string>
<key>SMexternalclock</key>
<string>333</string>
<key>SMmaximalclock</key>
<string>3160</string>
<key>SMmemtype</key>
<string>19</string>
<key>SMmemspeed</key>
<string>1066</string>
<key>SMmemmanufacter_1</key>
<string>Kingston Technology</string>
<key>SMmemmanufacter_3</key>
<string>Kingston Technology</string>
<key>SMmempart_1</key>
<string>KHX8500D2/1GN</string>
<key>SMmempart_3</key>
<string>KHX8500D2/1GN</string>
<key>SMmemserial_1</key>
<string>XXXXXXXX</string>
<key>SMmemserial_3</key>
<string>XXXXXXXX</string>
</dict>
</plist>
Of course values like the motherboard ID, boot ROM version and the mac model go together, so if you'd rather have an iMac7,1 you also have to change the other values, and not just the model ID. I found and verified these from various sources using google and I believe they are accurate.
The geekbench results site is a good place to start to grab some of the basic info, but be careful - many of the results posted there are clearly from hackintoshes with incorrect or incomplete smbios settings (Mac Pro with iMac boot ROM for example).
Authentic serial numbers, complete boot ROM strings and other stuff can be found on Apple and other Mac support forums. There are also threads on InsanelyMac, ProjectOSX and other OSx86 forums that have collections of some of the more hard to get info. Good hunting.