Well after checking the scale currently existing in the binoculars (It's in black so difficult to see unless you zoom in the graphic) but unimplemented due to not being also in the Alpha channel I found that it has .... 24 divisions!
(In fact 23 but with a half division on each side till the edge of the field of view)
Looks like we have a winner here
Too tired today, will try to have the TGA with scale somewhen this week.
Cheers