Here are some dimensions of my inexpensive springs that may help you source some:
Spring ID: ~15mm
Uncompressed Length of 1 Spring: ~85mm
Uncompressed Length of Combined 1.5 Springs: ~130mm
The approximate 130mm length yields approximate full spring compression, also known as fully "stacked", when the hatch is closed.
The ~15mm ID may need some persuasion to thread over the ball end of the hatch strut (or unscrew it and slide on shaft). Consider wearing gloves and safety glasses during this installation process.
Your results may vary.
