Thanks for your reply!
I've installed the Global 8.1 using the instructions provided in this post first and then downloading another image from here and side loading it (I think it was 'Rollback WW 2.13B Android 8.1 April 2018').
I personally did not unlock the bootloader, but the retailer I bought the phone from says they have 'root & flash to global Version' although when I got the phone the default language (for example notifications) were in Chinese, and the device showed CN in the build.
With the Google Services - whether I try to open the Play Store or login to a Google Cloud account it just gets stuck on 'Checking info...' and sometimes says there's a problem connecting (the internet connection is working fine since I can browse the web without a problem). I also looked at some logs using some tip I've found here and the logs show a connection error, something like 'unable to connect'
Given all the details above, and the information you've mentioned:In your opinion should Google Services be working without a problem in this case? What would you recommend trying next? Is there a way to verify whether the phone is unlocked/rooted? How do I check what's the current phone SKUID?
Many thanks for all your help