So i start applying the General Hauler parts to the Ore carrier but then spot something in one of the reference photos - this side on view of the front area clearly shows that the underside is much thicker than what i've got just by having the cage there, most probably i'm seeing the side of the larger scale stairs that Mat Irvine had used on the original.
That's it, mind made up - i'm going to have to junk the adapted ladder that came with the cage and use the real deal.
But, which one?
The EMA catalogue has a whole of different scales, so i took a chance and ordered the two sizes that they could be and, phew, one was right.
The other is far too big, but i've got an upcoming use for that, so all's cool.