Polysplines on strips of order $p$ are natural generalizations of univariate splines. In [3] and [4] interpolation results for cardinal polysplines on strips have been proven. In this paper the following problems will be addressed: (i) positivity of the fundamental polyspline on the strip $\left[ -1,1\right] \times {\Bbb R}^{n}$, and (ii) uniqueness of interpolation for polynomially bounded cardinal polysplines.