Here is how OLED screen looks like when actually displaying something
I use u8glib to control this SSD-1306 i2C 128x64 OLED display, but it's very flash-consuming. Adafruit library for this display is even worse. I have almost 3000 bytes left and I hope that it will be enough to develop some kind of graphics command string for drawing primitives. See how it was done in '80s in GEOS operating system.
This way Python interface would do the processing and prepare final drawing commands or even whole frame buffer and send over serial link. I have to keep in mind that refresh rate seems to be quite low. Besides, I have very vauge idea what should be shown there in each of three possible modes.
If 3000 bytes is not enough, I will move LCD code from Arduino Micro to Mini Pro and I will have some 6000 bytes left. Also LCD and OLED won't be on the same i2C bus anymore.