^ IIRC, I think the SJA spin-off series gave him a nod or two.
Sarah sugests Harry as a name for the Archetype before they settle on Luke. There was going to be a line in another episode which implied but didn't state outright that Harry had died, but it didn't make it onscreen.
Wider stuff.... it seems that the idea of having a young male companion started before Pertwee left, as Pertwee's back problems meant he'd have had increasing trouble doing the fight scenes if he'd stayed for a sixth year. Richard Franklin says that originally it was going to be Mike Yates rather than a new character, which makes a sort of sense (He'd have struck up a friendship with Sarah by that point, and have no reason to stay on Earth rather than go in the TARDIS), but maybe not. As a side note, Ian Marter was first choice to play Mike Yates, but was already booked for another job, so they hired Richard Franklin as choice two.
And Philip Hinchcliffe has admitted (in Lis Sladen's biography) that if he'd seen how Tom/Liz/Ian worked onscreen before he decided to drop Harry, he would have kept him. He reckons it was a mistake to break up that team, even though he saw the 'chap' as an unnecessary role in principle.