Surely if you lift the lid of the case you want the screen of MBP to come up as well? (I only hope I know what you want)
I did think of tacky stuff, but what could you use that would survive for many years without depositing exotic chemicals on the pristine surface of your beautiful MBP?
To Sesshi, you don't know what you want. I know more about what you want than you do, so pipe down! 😛 You don't want just a slipcase. You want an uber super duper carbon fibre reinforced aluminium coated bulletproof watertight shell that folds open, and dissipates heat, keeping your beloved MBP at sub-antarctic temperatures.
Yes I'd forgotten about the locking port/slot thing.
Well, it seems to me that there isn't much point in this thread being active anymore, as no-one knows of the existence of what the OP wants.
Good luck with whatever happens.