You could DIY it with a milling machine.
Measure the steps in the fish scales, measure the radius (or diameter) of circle required
step left to right polishing complete circles
step down one radius distance
step across one radius
then step left to right polishing complete circles (this will hide the original lower have of the preceding row.
Repeat this process for the area of plate you need.
Stain to match then seal.
Or you could scan the finish (or take hires photo with measure for scale in shot) print 1:1 - bond to blanking plate seal surface.
You need to search for fish scale polished effect.
Or go to a water transfer place they could capture you dash reproduce it and coat your plate.
