I've never seen one like that in a molded trailer before, but there's a lot I haven't seen! I have seen similar set-ups in older motorhomes over the front seats.
It could be factory or it could be a previous owner mod. There are some
Amerigo documents in the Document Center. Click the "More" tab top right above your log-in information, choose Document Center, scroll down to Manufacturers, and select
Amerigo. If it's factory, you might find some information there.
Looks like you remove the post in front and it swivels forward and down, reverse to raise. Some white lithium grease at the pivot points would probably help it move smoothly.
I expect the four support points have a wood block behind them to distribute the stress. You could pull one corner loose to see how it's attached and whether it's still solid. Even so, I'm pretty sure this was intended for a small child only.