Static spherically symmetric solution (Schwarzschild problem) in isotropic coordinates in Einstein's gravitational theory

In textbooks the full Schwarzschild problem is usually presented in Schwarzschild coordinates. In the Projective Unified Field Theory (PUFT) these coordinates lead to specific difficulties, whereas isotropic coordinates have the advantage to give explicit results for the exterior solution. Up to now the interior solution in PUFT has had to be treated numerically. For such an approach it is useful to know the interior and exterior solution (including matching at the surface of the sphere) of the Schwarzschild problem in isotropic coordinates in the Einstein theory which can be considered a special case of PUFT.