This is a classic New Orleans water meter cover. It has two layers so that it can easily be made in two colors. I designed it 220 mm round (Approximately 8 5/8"). It can be reduced in size but only to about 50 percent before the letters start to disappear from the print.
If you would like to use this commercially, IM me and we can discuss it.
I created this file from scratch with Tinkercad.
The author marked this model as their own original creation.