This paper continues the work of [16] and is concerned with the inverse problem of parameter identification in variational inequalities of the second kind that does not only treat the parameter linked to a bilinear form, but importantly also the parameter linked to a nonlinear non-smooth function. Here we specify the abstract framework of [16] and cover frictional contact problems as well as other non-smooth problems from continuum mechanics. The optimization approach of [16] to the inverse problem using the output-least squares formulation involves the variational inequality of the second kind as constraint. Here we use regularization technics of nondifferentiable optimization from [10], regularize the nonsmooth part in the variational inequality and arrive at an optimization problem for which the constraint variational inequality is replaced by the regularized variational equation. For this case, the smoothness of the parameter-to-solution map is studied and convergence analysis and optimality conditions are given.