The original PAL disc is by and large cropped to the left and right.
By adding black bars it prevents further loss of film width into the overscan region of a TV set.
The aspect ratio seems to already be correct therefore I am only resizing smaller and adding black bars to the left and right to ostensibly make up for missing frame.
Now I did go a little further than what was actually cropped since they probably cropped around 45 +/- lines total and I'm adding about 38 lines per side which is the approximate width of most overscan regions.
It's still possible that I might split the difference and only add borders to make up for actual missing lines (but evenly on both sides).