Notes on 7 Segment display that I have used. Mostly to jog my memory if I return to the project. Perhaps you'll find it useful too.
5 inch 7 segment
I bought several of these 5in. 7 Segment LED Common Cathode Display, Red at MPJA
LiteOn P/N: LTS-50301HRB data sheet. I didn't see the pinout on the data sheet. I wrote it on the backside with a sharpie.
Serial driver for large seven segment LED displays at Tindie.Com