Just a short update today (for now). I've downloaded all of the raw Hubble data targeting Pluto, from the FOC (Faint Object Camera) and ACS/HRC (Advanced Cameras for Surveys/High Resolution Channel). I am in the process of converting these images to more usable products and will create a gallery for these for anyone interested in the data.
For more raw Hubble data, I recommend this particular archive search engine. When looking for objects such as Pluto, be sure to spell it in ALL CAPS and change the 'Resolver' setting to 'Don't Resolve'