I'm just guessing here, but given the timescales we're talking, and the equipment in use at the time, I suspect a lot of these inconsistencies are down to the fact they there was no such thing as a standard jpeg, targa file, logo etc in those days. There was a house style for logos such as those for copyright, yes, but the exact kerning, line spacing etc was often down to the Aston operator on duty at the time. It wasn't an exact science. Many captions transited by presentation were framed up by cameras pointing at stills and while those generated by the infamous Noddy camera may have been of a relatively standard size, but the colours may have drifted slightly (see Cox Box), captions generated by programmes and news programmes in particular will have been done on an ad hoc basis.
There's a video in YouTube of a north west contribution to the classic nationwide programme, where regions provided national contributions to the main programme with various stories of interest. Each region idented their output with a logo with Manchester, Southampton etc written beneath it, and this logo was still often referred to as "The Mandala". (The former Nationwide title sequence had lots of Orange and yellow NW logos formed in a circle rotating, and looked like a bit like a mandala
https://en.m.wikipedia.org/wiki/Mandala)
The video, and I'll post a link to it below, is of a rehearsal for the network contribution and has production talkback on it from Manchester, you can quite clearly hear the director framing up one of the cameras pointing at a caption stand with the north west mandala on it, making sure it's not too big and in the right place on the screen. When Manchester cut to Leeds to send it down the line to London (only Leeds or Manchester could be fed to London at a time) it's quite obvious Leeds' Mandala is totally different in size and position.
