If they're oem based, to fit a g28 I believe they need to be modified in the way that the offset is not as wide. On this forum there are dimensions for oem hinges including modified ones that will work with a g28. No bulls shows why they need to be modified.http://lamboclone.com/index.php?topic=14.0
These look pretty good to me! Where did you get the plans? Do you mind sharing them?