Hi, anyone put a cube van GRP top onto a standard pick up? Will the plastic trims hinder fitment/need to come off? Are the 8 bolt holes accessable (or even present?) on a pick up?

That's how they make the cube van, so DIY should be possible. Cube vans don't have the plastic trims. Alot of people go the other way to convert cubes back to pick ups, but are often hampered by a shortage of used tailgates.