Battle of Northern ITV V Southern ITV

No. I think what happened was that the Lunchtime showing was the same as the evening one. In the early days, when it was shown in the morning and the afternoon, with no evening broadcast, the morning edition was a repeat of the afternoon before. After it was moved to 17:35, or 18:35 in Northern Ireland, it became the case that both transmissions were the same episode.

Just a thought as well about advertising. There used to be Mondays Newcomers, which showed new adverts that the ITV companies could record, and there was also, in the 1970s, a sequence where schools programmes were suspended between 10:30 and 11:00 each morning, to allow the ITV network to be used to distribute last minute adverts to all the contractors. Could that half hour gap have been used, if the capacity existed, to distribute entire programmes to contractors to show at a later date?

And when did the half hour break end, year wise, and why?

You couldn't splice 1" because it used helical tracks, it was only 2" Quad (a much earlier format) that allowed for physical editing.

You could have EdiTeced it - by laying clocks onto the tape first and putting them into record using insert (i.e. editing the recording onto the end of the clock) but there was no real need to do this as you were timecode syncing the two VTRs and running them in sync rather than cross rolling from one to another. You wouldn't be offering the VTR outputs to network, you'd be running in your own area offering a single, switched output to Network. They would never have seen the clocks if you did have them. If you needed a PasB of the final show as a continuous recording, you could book a fourth VTR to record the incoming feed (or record on site if an OB rather than a multilateral feed from an international event)

There must be stories of that going horrendously wrong?

Yep - in the days before servers (Profile's arrival in the mid-90s was a real game-changer), you either had to get a cloned tape in advance, arrange a line-feed in advance (and record it locally), or as you say, do the tape-delay shuffle. Which was horrible, and even more horrible the shorter the delay and the longer the programme. You needed three VTRs (any of which could be timecode slaved to each other), and someone running them who knew how long they took to rewind, and didn't push their luck in that regard... I'm not sure if the Nations did this that often, if at all, but network did when they needed to delay a live event (though it was usually a BBC Events AP who did the delay, not a pres person ISTR)

He then paused on a deodorant advert which featured a glimpse of a woman's breast, and paused it at the most revealing moment for some time, before the station abruptly came off air.

Physical splicing was only a thing from the Quad era, and used very sparingly (playing the tape over splice points was like hitting the heads with a hammer, and would shorten their life)

Rowan & Martin's Laugh-In must have killed the VTRs!

Didn't the evening showing of Home & Away on Friday used to span the Thames/LWT split, or am I mis-remembering?