The small OLED display arrived and after an hour or so getting it to work I hit another problem. The Arduino Uno didn't have enough memory space to store all the new library instructions. Fortunately I had a spare Arduino Mega which has oodles of memory space so transferred everything to that. The sketch (program for the Arduino) now consists of nearly 200 lines of instructions which compile to about 20K (20,000) bytes of code with nearly 2K of additional space needed for storing information.
This is the OLED display:
It consists of an array with 128 dots across by 64 dots down which can be made to glow like light emitting diodes. Unlike TFT screens it has no need for a back light so the background stays a deep black. Even though the display measures a fraction less than an inch it is very easy to read the lettering.
The thin wavy line seems to have been a foreign body on the display as it cleaned off this morning. My only concern is the temperature the display reaches. I picked it up after it had been on for a few hours and nearly burnt my finger. An IR thermometer showed part of the back had reached 40C. It does have a working range from -30C to +80C so maybe that is normal.