OK!
I would have used two parallel tracks, on which the platform could ride up and down.
Each should have a wheel or a pin inside them you can move over (like curtains hangers, but naturally something way more masive).
To each such wheel I would attach a hinge, that opens upwards, to which I would attach the deck itself.
So far you should have two parallel tracks to which the shelve to be be attached through a hindge and a small wheel, so it can be moved up and down and rotate upwards.
Next step I would have take two supporting shelf-hangers, and add pin or a bolt to each in the location they are usually being attached to the wall.
Than I would attach them to the deck on the lower side.
Last, I would drill small holes in which the bolts could get into, on the right hights so that the deck get set on the right side.
I hope I generally gave you my idea.
If you have any questions or if you think a drawing could help, feel free to ask
hinge