Just upgraded to f.28, followed your link. Works with Probook installer b8.
I had already upgraded to F.28. Do I choose the F.20 DSDT from the Probook Installer b8?
Gonna try it. It works fine, at this point except for Chimera, which was working before. I'll tackle that next.
I'm on my 4530s now with OS X Mountain Lion!
I'm dual booting with Windows 7.
To answer my own question, I chose BIOS version F.20 and it seems to work fine.
I reinstalled Chimera 1.1.1.