I layered the sample pic over the same shot from the SW blu-ray and it seems the most matching result was 720x246, so it wasn't as off as I thought.

Anyway, try using this for upscaling:

nnedi2_rpow2(rfactor=2, cshift="spline64resize", fwidth=720, fheight=960)

Probably the cleanest upscale method I've encountered so far.
After that, do the median thing and see how it comes out at 720x480.

If you want to resize it for an NTSC DVD sometime, use this:

Spline64Resize(720,292).AddBorders(0,94,0,94)

That makes it come out the same as it would with 720x246, just with some added resolution for the 16:9 ratio in NTSC.