In 1980 there were basically 2 choices to record an interview, 16mm film or a three tube analog video camera.

The chroma and luminance look like what was possible with the very last versions of 3-tube cameras; they phased out of production around 1982, but were still used until the 90s because they were superior in resolution to the CCDs of the mid 80s. A 1" Type C studio tape as original source could easily produce a picture of this quality if it was transferred straight to digital. So could 16mm film transferred to to 1" Type C then to digital.

The distortion at the bottom of the video looks to me like the video was originally on NTSC and was transferred to PAL format, and the overscan wasn't cropped.

Either way, this isn't an amateur production. It was either recorded by professionals in 1980 as it claims, or was faked by someone with at least a modest budget much more recently.