In today’s 10.1.7 PTR build, previous Engineering Goggle appearances are now available for all armor types by unlocking them via crafting achievements.
You’ll need to craft all the goggles from each of the 5 specific expansions in order to receive the appearances (Ensemble: Chromatically Calibrated Holo-Gogs/Black Holo-Gogs). You’ll be required to learn the appearances on an Engineer, but then they should be available to wear on non-engineering characters at least according to PTR data.
