Well, I tried install to the identical pen drive that booted Void Linux Live, and repeated what I did to grub-install, and the resultant USB drive booted! However, the boot sequence died running the initramfs, just after running dracut on the first partition of my HD [/dev/sda1]. I have aleady seen my error in the grub.cfg file [scream]. This is going too be hard work, but worth it in the end [?]. Just got to remember how grub.cfg is coded..