I can't help but think that maybe the hydraulics need to be properly bled. Only because it sounds like mechanically it is together correctly and you say the fork moves but doesn't appear to move far enough. A hyd. system with air will still let it move but not far enough once the load of the pressure plate is met. Just a thought and probably worth trying.
![Fingers Crossed :crossed:](https://board.marlincrawler.com/Smileys/marlin/crossed.gif)