The HP TouchPad 4G is very rare. So rare that I dont think they even released it like they did the WiFi version. I dont know whats more rare. The 4G version or the TouchPad Go. Chances of it working now are slim since no one really owns one. A lot of the developers are over on RootzWiki. Maybe try asking there. It could be something as easy as changing some code in some random file. But I wouldn't know. Good Luck.
Galaxy Nexus (Kitkat), HP TouchPad (Jelly Bean)
Palm Pre Plus
Everything before that doesn't matter.