Answer: As mentioned in the Flashstock.bat upon completion (during a normal Flash Stock + Unroot), if you are getting messages about not meeting certain flashing requirements (like bootloader/baseband version), you can either:
– Enable Force Flash Mode in the toolkits main options menu and try again; or you can –
– Selectively flash the required files using Advanced Utilities, Flash (Permanent) buttons.
If you decide to selectively flash the required files using advanced utilites, you can get any of the files you need directly from Google’s factory image packages:
– Simply download the one you want from here: https://developers.google.com/android/nexus/images
– Unzip it multiple times until you can see all the img files using an archive utility like 7zip
– Alternatively you can look in the toolkits /data/Factory_packs subfolders, which contain the extracted files for packs you have previously flashed.