Might be a Realm first here, simple as it was! It became almost immediately clear upon getting the Black Series Sandtrooper that he was going to need an alternate head. The most suitable extra head I had that fit the bill was from an ML X3 Movie Juggernaut. I simply dremeled out the housing in the head so it would fit on the ball joint. At first I thought it looked too big, but compared with the helmet it is almost spot on.
Summary of official OT / EU background on Davin Felth:
Imperial stormtrooper # 1023 who discovered that the escape pod that the Empire is looking for contained droids. He kills his superior officer Mod Terrik after becoming disgusted with the Empire's tyranny, giving the Millennium Falcon the time needed to escape from Tatooine.
Prior to his reassignment to the Outer Rim, Felth was a leading candidate to become an AT-AT pilot under General (then Colonel) Maximillian Veers. During his initial training evaluation, Felth deftly piloted an AT-AT to its knees to fend off attacking speeders--he had reasoned that the long legs and underbellies of the craft could be exploited. Instead of acknowledging and rewarding the trooper's findings, Veers, who had heavy financial stake in the AT-AT, covered up the exercise and transferred Felth to a Sandtrooper detachment.
Thanks for looking and God Bless!