Re: lowering 147 seat
I also had limited movement on my drivers seat, couldn't get it to go down far enough, It was sitting higher than the passenger seat and wouldn't go any lower.
So i took the half moon plastic cover off and released the handle mechanism (3 torx screws), this disengaged the seat from the handle mechanism and allowed me to push the seat down and then re-engage the mechanism, replace torx screws and fit plastic cover.
Did this a while ago so is from memory but hopefully you will see.
Hope this helps