Delica Canada | Mitsubishi Van Club

Hello!
I've got a 1999 L400 with captains chairs in the second row.
I'm trying to slide them as far forward as they will go in order to build a bed platform.
They slide pretty far forward and then they stop - but it seems like there is still some rail left so I'm wondering why they won't go all the way forward.
I've investigated inside the sliders and there isn't really anything obvious that can be adjusted to allow them to slide further.
Has anyone seen this before?
Kind regards

There is a stop welded to the seat frame that limits the movement that has to be removed. It's there so the person sitting in the middle row is not too close to the front seat in the case of a collision.

Andy