One thing I've really been noticing with these repeats is how much smearing there often is on movement. I know it's a side-effect of the old tubed cameras, but it seems more pronounced than I've seen on a lot of other stuff from the time. I wonder if any up/downscaling from HD (as I'm recording from the SD channel as it uses less PVR space) exaggerates it? There seems to be momentary bits where the picture looks "filmic" too which I imagine could be up/downscaling equipment that detects if the picture is 25p or 50i, but sometimes treats 50i as 25p, especially when there's not much movement.
I've seen the effect you've described with over zealous use of digital noise reducers. Noise is bad news for emission level encoding ( aka Freeview, Sky, Freesat transmission) because it soaks up a lot of encoding overhead. So if you can reduce the noise, and any PAL artefacts before transmission all the better. Done well, it can look really good ( eg TOTP repeats on BBC4) but overdo it, and you end up with weird and random motion artefacts, and a foggy look