definition of figure of merit of galvanometer:
It is the amount if current it takes for unit deflection in the given galvanometer.
k = I/theta
Where k is the figure of merit, I is the current supplied and Theta equals the number of divisions of deflection.
Is not it just a matter of calculation? What you would like to be simulated?
Let me know what you have in mind and I will try to create a simulation for you!