hairy_hen said:

Aren't they on the PAL '95 laserdiscs?

Yup
Moth3r's & Citizen's are where I first met them. GOUT has 'em too -- beneath the DVNR layer.
Look closely and you'll see artifacts.
And msycamore is correct: they're not apparent on JSC, but that doesn't really prove anything for certain.
It's not too difficult to imagine for example, the IP might've got damaged during the seven years after JSC was published.
But again I say, I think it's not the same IP/print/whatever-film-source
as JSC. Pictures at eleven...

hairy_hen said:
Incidentally, what sound mix does it have?

Ooops, I meant to include that in the O.P.
It's coupled to the main reactor in seven locations ;) although I've not compared dynamics et al against the other three SWE pressings.

Incidentally, my S/PDIF project is fully armed and operational.
One of these days, when I'm bored, I'm gonna rip all my LD's and post 'em....