It seems impossible to find a pure android 2-in-1 tablet/laptop. The only two brands that came up were ASUS and Sony and did not want to go with ASUS at this point based on past experience but then the Sony was priced way too high for this purpose. On the other hand, if we look outside the Android ecosystem, Apple tablets does have plenty after market keyboard options including ZAGG and Clamcase Pro.
Looking forward, it seems that windows is now dominating the natural 2-in-1 market with most of the major PC vendors selling windows 10 with Tablet and Laptop hybrids. Definitely seems that Google missed that opportunity by wasting time on the Chromebook when they could have opened the hybrid market especially for low to medium priced offerings with Android.
One good option with the windows tablet approach is that there are several emulator software that runs Android on a PC. This means you could have the best of both worlds and indeed it does work..
The moral of the story is that Google missed this opportunity and we are pretty sure there is a market out there for a well designed android tablet hybrid. At this point, you either go Apple Ipad with Clamcase style keyboard or stick with the many windows options reluctantly.
Enjoy the hunt!!!