Hello! I know, it's been a long time. A recently released into the wild video has turned up. From June 14, 1985 Bravo TV (Germany).
I can't take credit for the transcription. This is from the fabulous digital illustrator, Nika Purkis. Thanks Nika, you're awesome!
Text borrowed unceremoniously from Facebook (of course posted with kind permission from the amazing lady Nika):
Ok,
here's a first go at transcribing/translating (I stuck to what was
actually said by the guys as best as I could, please correct where I
misheard stuff!) This was highly entertaining 
==============
{on the tube}
Guy:
{starts mid-sentence}…this is not the case anymore with the dudes you
are about to see, they are among the top stars of the international
music scene…
Lady:… and are currently recording their new album at Battery Studios. This is Talk Talk!
{outside Battery Studios}
Lady
VoiceOver: On this road in Northwest London is where Battery Studios
are located. From the moment you step into the place it is obvious that
only top quality work is produced here. From Iron Maiden, Yes, to
Cars..this is where only the best musicians come to record their stuff.
{TT walking in}
Lady
VoiceOver: And when these guys are in productive mode it’s well
possible to catch a few funny quips during the interview as well. The
boys are really just up to mischief.
{the piano scene}
Mark: This is a piece from our new album.
Lee: That’ll probably set the single. {?}
Paul and Mark: yeah…
Lady
(VoiceOver): A track from the new album? well, that doesn’t sound
promising! One “plang” on the piano, and stupid faces. They are taking
the piss, right!?
{She’s asking them something inaudible while sitting down, Lee says "I’ll sit here" but I didn’t catch Mark}
Lady: You’re working now on the new record?
{I can’t quite catch what Lee’s saying..”there’s a something here”? }
Mark: yeah.
Lady: What’s gonna be the name of the record?
Mark: Don’t know that…. Don’t know.
Lady: And when is it gonna be finished?
Mark: Uh..about 2, 3 months? 4 months? September, October perhaps. Unless it takes longer.
Lady: When you began with Talk Talk, Mark, didn’t you have the wish to be a pop star?
Mark:
No I only ever wished for one thing…and that was that I could sit here
and do this interview with you right now… {laughs} it’s beautiful
innit…it’s beautiful.
Lee {laughs}: beautiful…beautiful
Lady: Ok, but seriously now: what does your recording process look like?
Mark:
ah right. Lee comes in, right, and he starts hitting things. And we all
go ‘ah stop that bangin’... stop that bangin’.
But he won’t, right,
until someone says: if we tape it…will you stop banging. And he’s yeah,
alright,… and so we tape it, and he stops banging.
And then Paul comes around, …..oh that awful noise..that noise…dum dum, dum dum….so we tape that.
Lee: …and then we invite people down to make noise…
Mark: Yeah…
Lee: …so we can put it on tape.
Mark:
Yeah. Trying to make it a bit better, with just him and Paul this thing
is terrible. It is rubbish. It’s absolute rubbish. So we invite people
who can actually play, to make it sound nice. And that’s it really.
