There is only one episode of the Space Pirates serial which remains and to be honest that is probably a good thing since it is full of silly characters (the ol' timer space cowboy with the terrible accent and facial hair) and lots of authority figures who give performances so stiff and unnatural that I assume they must also be the guys who are inside the suits for the Ice Warrior or Cybermen. So no great loss but the good news is that I'm told this the last serial to have any missing episodes and as such it seems like a time to reflect on that.
It really is hard to comprehend how so much was lost and that anyone would look at a very popular show today and think "well, we've shown that already so we'll not need to again" and scrap it off. Imagine the idea of Fox just deleting the masters of The Simpsons or HBO doing it to The Sopranos – it seems like such a stupid situation that it could never happen. I understand why it was done, but it still amazes me. The more amazing thing really is how many of the serials and episodes in the first 6 seasons actually do exist, and I did enjoy reading up about how these had been recovered by the BBC but also by the efforts of fans. For all the episodes audio recordings are available due to fans and the recently recovered episodes continue that trend by being more to do with the passion and efforts of individuals rather than the BBC themselves. As much as I may have moaned about the missing serials (particularly in the Troughton era) it is impressive that as much does exist.
You can see this in the Doctor Who fan community because the efforts and excitement over the possibility of recovered episodes really does seem to engender a passion for discovery and an appreciation for what exists. I'm not near this level but I confess that, as I watched through the old serials for the first time, it was pretty exciting to have new ones suddenly pop up in my path (as Web of Fear etc did). The good news is that this is now the end of this policy and there are no more missing episodes moving forward after this serial. I'm sure I will regret this as I reach some of the Sylvester McCoy era serials, but for now it is a good thing and it is just a real shame that Troughton was such a victim of this as I really did enjoy his Doctor a great deal. I'll never be a part of the fan community in the way others are but for sure the news of episodes or serials being recovered in the future (as unlikely as that is) and I'll be right back to watch them with excitement.