Replacement

[Forostar]

I think maiden is really unique in this situation. Maybe it's because they've never been confronted with this problem. But other bands, like Pink Floyd for example, can have a stand in and no one seems to care but I think if anyone got replaced for a show or tour, (except for maybe Janick, which is unfortunate) a lot of people would be really disappointed.

As far as I'm aware, Maiden never took other people to temporarily fill in for a member.

Maiden has dealt with members who could not play:

I don't recall a gig cancelled because Steve or Nicko couldn't play (the men of iron).
Not sure about Clive, or Dennis. Maybe some gigs were cancelled, but I don't know for sure.
When Bruce or Blaze were not able, the gigs were cancelled or rescheduled.
In the occasion of Paul, the same, though there is one famous occasion where Steve did the vocals, because the gig was terribly important.

H, Dave and Janick? Answer here. In this line-up Maiden has played without Adrian, but not without Dave, and not without Janick.

So: If my observations are correct, historical facts guide me towards my imagination of the following:

Maiden never replaces members, in the situations described by the topic opener. End of discussion.  
No seriously: what has not happened, could still happen, we can never know... 

 

[mtmccox]

In the occasion of Paul, the same, though there is one famous occasion where Steve did the vocals, because the gig was terribly important.

I'd love to hear that

 

[Forostar]

No audio I'm afraid! Wasn't this the gig Paul was arrested? It could be that Paul still arrived later on the show and did some songs. The story is in the biography, and maybe some words about it as well in The Early Years DVD.

 

[Mosh]

It was when Paul got arrested. That is the show where Rod came to see them and they had to go on.

 

[Night Prowler]

Janick injured himself during the Blaze era and, though Jan was still able to gig, Davey had to do all the solos until he got well again.

Pictures/videos/audios or it didn't happen

 

[Mosh]

Wasn't that when they did the TV special? I think Foro posted that video here before.

EDIT: Yes he did:
http://www.youtube.com/watch?v=2gBmfqD26AY

 

[Forostar]

He might have meant that but that's not a full concert, just playback of one song, so this doesn't count.  

 

[Mosh]

Ok. Well it doesn't say anything on the commentary so I don't think it's true.

Also I noticed that they cancelled shows due to Blaze quite often. And some of the venues they played were really small. (I knew they were smaller but comparing the Ogden in Denver to Red Rocks that is a huge difference)

 

[Forostar]

The venues in the USA, yes. The metal climate was pretty dead out there.

 

[snake plissken]

Pictures/videos/audios or it didn't happen

I remember reading it in a Maiden fan club newsletter (can't find those old things). Deffo during the Blaze era. Totally happened, up to yourself whether you believe me or not.

 

[Mosh]

The venues in the USA, yes. The metal climate was pretty dead out there.

Kind of still is. Not that bad though.

 

[Ranko]

First-hand testimonies about the two aforementioned occasions can be found in the Steve Harris book. First, Paul Di'Anno mentioned in his interview that Steve had to sing the entire Maiden set once when Di'Anno was arrested for flashing a knife in public, that was the night when Rod came for the first time to listen to the band, wanting to decide whether to accept managing the band or not. The second thing was when Tony Newton of Deeds replaced Janick during a tv appearance because Janick's mother was ill and he went home to be with her. Anyway, Steve told Tony that he would only be visible in the wide shots of the entire band, that there would be no close-ups and that there would be no audience. However, there was an audience and the rest of the guys made sure they were close to Tony so he would end up in almost every close-up shot.