I purchased a Chinese Huawei Media Pad M3 8' WiFi tablet in March 2018 with the following details.
Model: CPN-W09I wanted to get google services on this device. This is what finally worked for me.
Build: CPN-W09C233B066 , CPN-W09C233B067 (updated 8 Apr 2017 with no negative effects)
Startup the tablet. Select USA English, skip Huawei registration and Wifi. Skip cloud services, enable pin, enable fingerprint ID. Get to home screen.
Connect to computer, enable file transfer and drop GSM the gsminstaller apk into your download folder. Install the gsminstaller and after the installer is installed, open it and press the 'one touch installation button'. After that, I installed Google Play service 12.5.20 and Google Play store 9.3.14 both of which I downloaded from apkmirror.com.
I was able to log into my google account and everything seems to be working fine. I even reset the tablet to factory specs to make sure I had the right steps and it looks like the GSM core stayed installed.
Note I got the link to the gsmcore (gsminstaller.apk) from this thread. so thanks.
Also, as I researched this, I stumbled across a couple of other tidbits that I thought I'd put here.
There are some hidden menus you can reach by putting the calculator in landscape mode (so you can see the '(' ')' characters.) and keying in the following combinations.
To get the Product ID enter: ()()1357946()()=Hope this helps someone else.
To get the Project Manager (install firmware from SD card, reset etc) aka Manufacture Mode enter: ()()2846579()() =