You can also make your usual h:mm and H:mm aligned right
and place separate extra 0 text in front of it and let it display with expression for opacity like ([H]<10)x20 for 24h form
and like (([H]>0)x([H<10)+([H]>12)x([H]<22))x20 for 12h form (put * in place of x)
Sorry I do not feel it being fair to “dismantle” each feature on specific Jeweler’s watch face.
I think I provided enough info how multiple changeable overlapping images can be put on watch face.
I can not explain how to make it look good. That is each designers added value.