No luck opened up, but I'll try tomorrow to see what I can find online, here's two more shots of some detail, and yes its a rail/truck ramp. There's bars on the ramp, and a mesh too for trucks. I also saw in a pic, it says "L 89-4" so maybe it is 89'? Of note, it opens, in 5, 5 1/2, or 6 parts depending on how you look at it, there's 5 main parts and a final what looks like 1/2 piece, the diagonal portion across the middle, that you can either choose to no count, count as a half or a whole.
EDIT Also, note what look to be MU... ;-)