[Steve in Pudsey]

That kind of switch from VT to the originating company's dirty pres output was routinely done for promoting books and records which accompany the series so it's not beyond the realms of possibility but unlikely as you say.

Tony Currie mentioned at the blue place that Scottish had a copy of each station's generic endcap, I assume that was common practice. So each company would have been able to do their own version of that filler sequence - I imagine they would have been expecting it to fall off air after the issue with the first half.