WooHoo, I finally did it! Got to Official Firmware 2.1.1
I contacted Himedia, and they could only point me to 2 files, the first to update Android 5 to Android 7 with firmware 2.0.4, the to update to firmware 2.1.1. So I decided to try it, which meant I downgraded to Android 5 first, all OK in firmware 1.0.8
I used the first file, to go from Android 5 to Android 7 with firmware 2.0.4 but I seemingly had no luck, the robot progress bar only got to 80% then the Q5 rebooted, but I was left with a blank TV screen, and just 'boot' on the LCD screen of the Q5, no home screen at all, so no luck I thought.
Remembering all my previous attempts I realised that at this point before if I tried to install an Andoid 7 based firmware, 2.0.1 I did get the Android 7 rings when using the paper clip method, so I knew Adroid 7 was on the Q5, and working. So I upgraded to firmware 2.1.1 paper clip method, but not had a working Q5 since Android 5, and I waited, and then, hey presto - Android 7 and firmware 2.1.1 all good to go, with the official home screen, and old version of Kodi, but it is working.
I will take a deep breath and upgrade to Custom Firmware 2.1.1 and then, another even deeper breath, and try to go gor 2.1.2
Such a long journey, the scenic route, but I appear to be where I want.
Thanks to all.