  We investigate analytic continuation of the matrix cosine and sine transforms
introduced in Part I and depending on a complex parameter $\a$. It is shown
that the cosine transform corresponding to $\a=0$ is a constant multiple of the
Funk-Radon transform in integral geometry for a pair of Stiefel (or Grassmann)
manifolds. The same case for the sine transform gives the identity operator.
These results and the relevant composition formula for the cosine transforms
were established in Part I in the sense of distributions. Now we have them
pointwise. Some new problems are formulated.
