Hi Anthony,
Been away for a few days so sorry for the late update but I found some additional info regarding the ME fimrware error that may help.
http://h20628.www2.hp.com/km-ext/kmcsdirect/emr_na-c03424977-1.pdf
If you look at the document in the above link, (page 38 in the pdf, page 26 in the manual), you will see a reference to a jumper 36 which is labelled as ME/AMT flash override. Could it be a simple case of setting the jumper and running the ME firmware?
I remembered you have the earlier boot block date so the jumper may be in a different location on the motherboard.
Also, not sure if this helps but I've attached my BIOS settings FYI.
https://dl.dropboxusercontent.com/u/83715804/AdvisorConfig.doc
P.S. My HP Z620 is running Windows 7 Professional 64bit with a UEFI boot to a 256GB Samsung SM951 M.2. card located on PCIe slot 4 (via a ASUS Hyper M.2 X4 Mini PCIe card), a 480GB SSD in SATA0, 2TB 3.5" drive in SATA1 and 4TB 3.5" drive on SATA2. I also have a Syba SATA III card installed in slot 3 connected to a hot swappable ICY Dock 2.5"/3.5" drive bay.
