Found this on the net! http://www.youtube.com/watch?feature=player_detailpage&v=IbwtZLEzXuo And yes, this is actually Jon Pertwee.
My inner pedant feels compelled to say 'Jon.' Nice find though. Pertwee looked old though, didn't he? Not surprising that he passed away soon after.
That's from Devious (as the Youtube text sort-of says), a fan film about a half-incarnation between 2&3 that ends with him regenerating into Pertwee. That bit was shot around 1995, so just before Pertwee's death, but the full film was never finished. Some of Pertwee's dialogue was repurposed so he could appear in Big Finish's 40th Anniversary story Zagreus, and the console was used in The Curse of Fatal Death.
Psst. You mean "40th-anniversary story Zagreus." For what it's worth, I've never been able to make out what the third Doctor says in Zagreus. I'm keeping my fingers crossed that The Light at the End is good, but then I remember Zagreus and I get really scared.
Oh yeah, soz. Typed it in wrong. Teenagers.....:P Yeah, it was late in his life. Oh......I totally knew that...........:P I did wonder why the second doctor looked nothing much like Troughton. I just thought he was some geek who wanted really hard to look like Troughton. :P
Good find. Not bad at all. Still, I had seen a similar one that started out the Troughton morph to 2.5 (as that guy in Devious was supposed to be an interim Doctor - take that, John Hurt!), cut away to the rest of the body regenerating as well, then cut back to 2.5 morphing into Pertwee, thus making it seem like Troughton regenerated into Pertwee. I liked the idea of that, and combined with the Third Doctor's memory wipe could explain a few things. Sad that I cannot find it at the moment. All things said and done, its a lovely little scene by one of the more underrated Doctors. Pertwee's acting in his scene is a jewel - his "No!" is fantastic.