That's no fun! What would I do with all the hours of my life that I save getting the proper parts at the beginning rather than fitting all these dodgy old used ones in?
In all seriousness though, I'll probably just throw one of the Les Richmond Automotive White Tiger Spring Spacer Shims < White Tiger Spring Shim 6mm > under each of the low side and call it a day... The vehicle is only a cheap spare that does less than 5,000km a year and those shims should be very quick and easy to install as won't need to compress the front springs or anything.
Pulled the current fitted rear ones out and found on the upper half where the tighter progressive rate coil are a brown/burnt oranges and green paint markings:
Attachment 147545
With the replacement yellow/yellow rear springs installed the rear has dropped 50mm and is sitting lower than the front now - still uneven too! Thank fully the rear springs are much quicker and easier to remove with the top shock absorber being an easy undo and no spring compressors required!
So either pure bad luck, or it must be something other than the springs causing the vehicle to be uneven side to side given that I've just swapped out all the springs and it remains almost equally as imbalanced with the same high and low side...

