Modifing trunk lid springs for aluminum 300SD trunk lid on 300SEL

[ThePhoenix]

I had to replace the trunk lid on my 300SEL after some rear end damage, so after some searching I found a pristine replacement at the local pic-a-part in the same factory black color. The issue is that the new lid is aluminum because it came from a 300SD, so it literally flies open because the spring tension is all wrong.

I suppose I could go back and buy the springs and/or hinges, but perhaps someone here knows a way to adjust the tension of my existing springs? I haven't pulled the hinges off so I'm not quite sure what I'm dealing with yet.