You can change your serial# in the one that *is* being used.
I'm saying the serial# is not automatic. It is determined by the content of config.plist.
Refer to the Clover wiki:
http://clover-wiki.zetam.org/Configuration/SMBIOS
I know that, I've known that for a long time. We never seem to understand each other lol. I think you answered my question about the fsck, so I'm all good to go as far as config files and all that.
My computer is how I wanted it except for a plain grey login screen in Yosemite 10.10.5 that I can't get rid of. When I replace com.apple.desktop.admin.png in Macintosh HD/Library/Caches, it will appear as my custom desktop but looks foggy and barely transparent, but goes back to plain grey after a few reboots it seems. I've also tried deleting the com.apple.desktop.admin.png image and that doesn't bring back the default Yosemite login behavior either. It won't simply be blurred transparency of my current desktop background like it's supposed to be.
I've Googled the hell out of this issue with no good answers. One person said it's new to Yosemite and can't be changed, and every other link just tells you how to do a custom login screen which I'm not interested in. I thought of taking my desktop background and blurring it in Photoshop and just setting it as custom, but it doesn't work right because when you set a custom login screen, at least for me, it's very dark and barely transparent and it doesn't look good. Any suggestions?
UPDATE: Well, it seems that after I did some testing, the default Yosemite backgrounds show up properly on the login screen, with blurred transparency, but when I use a custom desktop background, it doesn't appear on the login screen. Gonna try and delete my custom folders set in System Preferences/Desktop & Screen Saver and re-add them, as one post I just read on here seemed to suggest.
UPDATE 2: Okay, I think that did the trick. It's hard to tell if my custom desktop shows up with the same amount of transparency and blur as the default Yosemite background in the user login screen, but I think I fixed it. It looks quite close so I'm assuming it's fixed. No more ugly, plain grey background.