Found some years back in the Boeing archive, artwork depicting a ca. 1967 Boeing concept for a Saturn V-launched space station. A dry-lab station built from Saturn V components, in this case apparently a shortened S-II stage.
The use of such a space station as a mounting point for large astronomical telescopes such as shown here is dubious. Vibrations, everything from solar panels being turned to air circulation systems to fluids being pumped to crewmen bumping around, would contribute to a pretty noisy image.