Another way to duplicate gussets is by using a manual punch press and a pantograph attachment. Back in the old days before CNC we used this method to duplicate metal brackets.
The punch press can hold different shaped punches. Squares, rect, obrounds, rounds.
I like to teach the kids the old ways before I introduce them to the CNC.
Here is a video of a manual punch press:
https://www.youtube.com/watch?v=W4hrxcdlVf8