Command Line – How to Put File into Clipboard Without Losing Control Characters

It's because values are written as strings not integers. You can see that using:

$ plutil -convert xml1 -o - ~/Library/Preferences/ByHost/.GlobalPreferences.*.plist

<?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>com.apple.keyboard.modifiermapping.1452-591-0</key>
    <array>
        <dict>
            <key>HIDKeyboardModifierMappingDst</key>
            <string>30064771303</string>
            <key>HIDKeyboardModifierMappingSrc</key>
            <string>30064771302</string>
        </dict>
        <dict>
            <key>HIDKeyboardModifierMappingDst</key>
            <string>30064771302</string>
            <key>HIDKeyboardModifierMappingSrc</key>
            <string>30064771303</string>
        </dict>
    </array>
</dict>
</plist>

So the right way to update the setting is using XML format:

$ defaults -currentHost write -g com.apple.keyboard.modifiermapping.1452-591-0 -array \
'<dict>
    <key>HIDKeyboardModifierMappingDst</key>
    <integer>30064771303</integer>
    <key>HIDKeyboardModifierMappingSrc</key>
    <integer>30064771302</integer>
</dict>' \
'<dict>
    <key>HIDKeyboardModifierMappingDst</key>
    <integer>30064771302</integer>
    <key>HIDKeyboardModifierMappingSrc</key>
    <integer>30064771303</integer>
</dict>'

Just a thought here, but if you can boot Linux, why not install ESX 5.5 (it's free to use in base form) and then just one VM, your Windows Server.

ESX has a very low overhead and you should get most of the oomph you need out of Server 2008r2.

The only question that remains is, "will ESX 5.5 install on an XServe?"