  We present a practical $S$-matrix to potential inversion procedure for
coupled-channel scattering. The inversion technique developed is applied to
non-diagonal $S^J_{ll'}$ for spin one projectiles, yielding a tensor
interaction $T_{\rm R}$, and is also applicable to spin-1/2 plus spin-1/2
scattering. The method is a generalization of the iterative-perturbative, IP,
method. It is tested and evaluated and we investigate the degree of uniqueness
of the potential, particularly for cases where there is insufficient
information to define the potential uniquely. We examine the potentials which
result when the $S$-matrix is generated from a $T_{\rm P}$ interaction. We also
develop the generalisation, using established procedures, of IP
$S$-matrix-to-potential inversion to direct observable-to-potential inversion.
This `direct inversion' procedure is demonstrated to be an efficient method for
finding a multi-component potential including a $T_{\rm R}$ interaction fitting
multi-energy $\sigma$, ${\rm i}T_{11}$, $T_{20}$, $T_{21}$ and $T_{22}$ data
for the scattering of spin-1 nuclei from spin-zero target. It is applicable to
other channel spin 1 cases.
