I had several issues with my original front end, at least it looked that way, original.
The trail was more than 4 inchs, best I got measured was 3.5", this also create a larger flop ratio, and they were bent and some one attempted to straighten them.
Okay when you do a front end, first things first, the wheel is done correctly and balanced. You need to know it is good.
Also why many buy new shocks, it is not an area to fudge on, okay that is my take on it.
Before buying any shock or spring you need to know front end weight along with rider weight, so that you can get the preload correct and functioning shocks or springs that operate correctly with your trike.
40 degree rake is not the best as you do get a higher flop factor with this rake than a 45 or greater rake. The flop factor will get smaller actually as rake increase past this point.
Just stuff I had to learn and understand so I could design and build my front end. I guess one can do it by try this and try that until all works, but that is not the approach I took or would recommend.
So glad you getting it worked out, it is always better to ride................