So did everyone else. He's in Shada, a Tom Baker serial that was never completed due to a strike at the BBC. It was completed a few years back with animation and voiceovers. Doug also reused Reg in Dirk Gently's Holistic Detective Agency, where we discover the only thing that can kill a TARDIS is hooking it up to the British phone system.
On a very tangential note...
...the frequent strikes in the UK in the 70s came back to haunt me when I was working for another TV company in the early 2000s.
This creepy little no-budget number was an April Fool's Day special for 1977, but another strike delayed it to the summer - accidentally War Of The Worlds'ing the UK.
Where do I fit in? Well, for the station's 40th anniversary, I put some clips online and a nice history site about it.
And got death threats.
And all the clips stolen, syndicated to a bunch of different sites, some re-edited with bible quotes to prove its authenticity.
Yup, conspiracy theorists believe to this day that Alt/3 was real (it wasn't) and was suppressed by the US government (it was).