Apologies for the delay - I *hate* it when my day job gets in the way of my CustoMac fun
But wanted to get back with you to say THANK YOU for supplying your EFI folder! That really helped a LOT - especially getting pretty much everything else working, once I got past the OsxAptio issue. And the secret there was exactly what
encierro shared a few posts after yours.
I seem to now have a fully working build - except for I believe power mgmt./speed step. And I'm OC'd at 4.3GHz, too! My TB card is working with my Seagate TB drive. I'll have to try a couple other TB devices (I've got a FW adapter & an Ethernet adapter, and a PCIe expansion chassis with a Blackmagic Designs video capture card). I was actually able to get it to work in the PCIe_16 slot farthest away from the CPI (instead of the little 4X slot).
So again, many thanks to you, and also to encierro for sharing the OsxAptio fix! I think I'm almost ready to start a proper build thread on my new Music Studio 3.0 CustoMac. Stay tuned!!