Migration issues no bootable disk

Restored W10.5 upgrade from W7 Home from iMac late 2009 1tb OSX 10.12.6 BC partition on same disk.
To MBP Mid 2012 disk 0 500gb Sierra 10.12.6 disk 1 target 500gb both are SSD. Note blind using VoiceOver for nav.
Restored both Win and block method and used legacy and EFI modes SIP disabled get No Bootable Disk when setting boot in Startup and Option. Only difference is EFI gives EFI boot during Optin load which brings me to Safe mode where I was able to log in and try loading BC drivers and Assistant. Reboot still gives same issues. Tim you’ve been helpful via email but decided to post this here. Is it possible it’s because I’m restoring to second drive where source was on main drive? Opinions?Note target partition was prepared exactly as spesified in instructions and is accessible in Finder and file structure looks ok.

where is the second drive located? Was it in the optical drive bay? We have seem issues with booting boot camp in optical drive bay on older MacBook Pros.

tim

Yes in SuperDrive bay.

Obviously the drive installed in optical bay is causing issues. Any workarounds? With my tests I sent you results privately in response to our other conversation.

I found a post similar to my situation on Apple discussions.

https://discussions.apple.com/thread/7633176?start=0&tstart=0

The difference is that BCA was not used in my case to create the new
partition on Disk 1 on the new target MBP.

I don’t have room to doo all this on my main drive and then move it to Disk 1.

Would the instructions for boot repair work for my case - remember the
only way I can get into the restored partition is through EFI-Boot
with current version not Beta.

Since my testing last night I can’t get into Windows at all now since
EFI was the only way prior to Beta and I’ll have to uninstall the Beta
and re-install the original version unless there is a work around to
update the Legacy MBR to point to the Disk 1 partition.

Then I have to figure out how to get that old BC out and re-try
loading the BC and Drivers again without error.