Hi, I know this will sound stupid at first but I'm having trouble fitting drivers seat in p100 and wondered if anyone can tell me what I'm doing wrong!

The previous owner removed them and left them loose in the back, now I am re fitting them.
the drivers seat has a long mechanism on the bottom of runner with a folded handle on the front. And basically this is in the way as there is a raised section on the floor pan, and I can bolt the front brackets down, but the back brackets are lifted up about 4 inches where the mechanism rod thing is touching the raised section on the floor. I have tried fitting the seat both with the mechanism wound out full and wound in, and I still can't get the back of the seat low enough.

This is really doing my head in! Please can some one point out whats going on? Thanks, matt