I recently found some of these old-school 4 digit by 16 segment LED displays on eBay and couldn't resist. They are the ones with tiny LEDs that are optically magnified to 0.16". Kind of like the ones in early calculators except alphanumeric (sort-of). Here is a pointer to the best data sheet
I could find.
These are 18-pin devices; lots of control pins and a 7-bit ascii character bus. I guess I would use one of the I2C I/O expanders if I was actually going to use these for anything.
Here are a couple of photos and a little spin program.
Re-inventing the wheel is not a waste of time if, when you are done, you understand why it is round.