DISCLAIMER: These are pretty much only for show, they don't function.
Security Center
For Security Center, you'll need the following files from a copy of Windows Vista:
wscapi.dll
wscui.cpl
wscui.cpl.mui
Rename wscui.cpl and wscui.cpl.mui to something different, but make sure both files have the same name (for example vscui.cpl and vscui.cpl.mui). This is to prevent a redirection to the modern-day Security and Maintenance/Action Center page
Place the MUI file in an en-US folder (or a folder that corresponds to your locale)
Open wscui.cpl in a hex editor
Open the "replace" dialog, and replace all occurences of wscapi.dll to something else, like vscapi.dll (make sure the amount of characters and extension stay the same)
Rename wscapi.dll to vscapi.dll
If you have the Security Center service on, it'll display everything as "Not Compatible"
If you have it off, it will say it's off.
Firewall
Get these files from a copy of Windows Vista:
FirewallControlPanel.exe
FirewallControlPanel.exe.mui
That's it. It'll just run.
If you click on any of the firewall-related links, you'll get an error complaining that FirewallSettings.exe was not found. You can get it and it's mui from Vista, but then it'll complain about a missing entry in firewall.cpl. You can get the Vista version of it and hex-edit FirewallSettings.exe to point to that instead, but then you'll just get nothing.