OK, I also have a schematic for a 38 Double Action as well, but the trigger spring is totally different design and function. For me, it is one of the toughest springs to get and keep in place when installing the trigger guard. It often shifts a little and does not work unless it sets just right. I think I have tried to get that spring in place on one gun a dozen times before it caught the trigger and functioned properly. I would keep trying and bet it will just drop into place sooner or later.
If I remember correctly, there is one leg of the spring with a bigger bend than the other and that always went down against the trigger guard.