Latest status update: So, I've been through many settings and while I can get Google Servers to show this as an official (with icon) NVidia Shield Tablet, I can't get it to spoof enough. I've been trying as a 4.4.2 device, just to see if that will work. I can still get it working great with MarketHelper, I don't want to have to run it after every reboot.
So, I'm going to keep trying until I can get this to work. I was able to pull apart Market Helper and noticed that it sends the OpenGL info, radios and even an application list. I wasn't able to find exactly what is bring sent fir the Shield yet. I've emailed the author to see if he can help, but I've not heard back in days.
So, not giving up. Never giving up. ;-) I WILL GET THIS WORKING!!!