Add peripheral Hardware where screen was I have been playing around with some old android devices. 

I took a broken screen / digitization off one LG and the device is fine. Running in shell and voice assistance do describe screen.

My question: Can I hook up some peripheral input or output where the original input / outputs were and write new drivers. I know this is a daunting task. But someone has to do it.

Basically the display should have a power + and power - I could hook a different device up to and when I unlock screen the device receives power. The input method is much more complex, I know. Looking for somewhere to start. Been googling for hours.!

I am keeping a journal of my activity here:
Google Doc
Not for the screen itself. The connector used for the screen is not for general-purpose input and output. It's connected directly to the framebuffer hardware, so all it can do is stream pixels very fast to the panel.

You might have more luck with the digitizer (touchscreen). It depends which particular interface is exposed. If it's only where the touchscreen "film" connects to the controller, then all you can do is replace it with the same touchscreen, because the signals passing on that connector are only the raw touch positions, which the controller interprets and turns into touch events. On the other hand, if the controller is on the side that's not present any more, it might be that the connector is on a SPI or I2C bus, in which case you can hook another SPI or I2C device, and you'll need to make a kernel driver in order to talk to it.

To go any further in this direction, you'll want to join our sister site, Electrical Engineering Stack Exchange, and ask there. They'll need a lot more details about the connections: photos, pinout diagrams if you have them, part numbers of any components on the downstream side of the connector.