Looking at that again, I suspect there are some interlacing issues I need to sort.
It definitely like it's interlace video that's been captured and treated as progressive.
I've done a lot of tape digitising over the years, the key is to always capture as 720x576 25fps interlaced, which is full resolution digital SD.
For sharing the clips (e.g. uploading online), it's best to stick them in to an edit application which is using a project set to 720x576 50fps, and then export using whatever your prefered codec is (I use H264). If you're dealing with 16:9 footage you will want to set your project aspect ratio as 16:9 and then export as 1024x576. I use Adobe Premiere which works really well for this as it has a decent deinterlacer, but I'm sure most professional edit applications will give similar results.
I thought you had to save it with 720x576 with a 16:9 flag on it.
If you are exporting for DVD or captured at 720x576 then keeping it as 720x576 (avoiding a rescale) and ensuring that it is encoded with a non-square PAR (Pixel Aspect Ratio) is a good idea IF your player and encoding workflow flags it correctly.
If you are exporting for viewing on a PC or uploading to a social media or streaming site you may be better scaling 720x576 to 1050x576 (not 1024) or cropping to 702x576 and scaling to 1024x576. In this case a deirterlace from i25 to p50 may also be a good idea. FFMPEG has a bit of a steep learning curve - but is well worth mastering. It's trivial to convert SD MPEG2 with incorrectly flagged ratios to a nice square pixel progressive version with a YADIF or W3FDIF 2x deinterlace and scale.
Golden rule with aspect ratios :
4:3 and 16:9 SD 50Hz are 702 x 576 NOT 720 x 576.
There are 9 samples either side of the 702x576 that make 720x576 slightly wider. They are there to avoid cropping overshoots/undershoots etc. (same reason we have black at 16 and not 0/1, and white at 235 not 254/5)
If you are converting between SD and HD :
HD->SD Scale 1920x1080 or 1280x720 to 702x576 and put 9 samples of black either side (or 704 + 8 if you have to)
SD->HD Crop 720x576 to 702x576 and scale the 702x576 to 1920x1080 or 1280x720.
And if you are scaling interlaced content - whatever you do make sure you deinterlace to 2x progressive, scale, and then re-interlace. Don't try to scale in the interlaced domain - or worse treat interlaced content as progressive when you scale...