I don't guess. They are easy to remove one at a time and compress hard on bathroom scales. Compare the readings in kgf for each side. These gas struts only play a small part and when the lid is near closed, just set the lid to balance with very little upwards contribution.I am guessing on the worn lid struts
The rear lid sprung buffer height is self adjusted automatically:
1. Press down and turn the top of the buffer 45 degrees.
2. Loosen a small clamp screw on the side until you can see it.
3. Pull the buffer top up slightly to make it higher.
4. Close the rear lid
5. Open the rear lid.
6. Screw in the buffer clamp screw to a depth of 20mm +5mm.
7. Press the buffer top down and turn through 45 degrees.
8. Check the setting in (6)
9. Repeat for the other buffer.