In the early 60's the USAF Scientific Advisory Board looked at a wide range of small MOL-like space platforms to be serviced by Gemini or Dyna Soar vehicles. I've made available a report on this study; it includes diagrams not only of these small space platforms, but also the Gemini/transstage-based satellite inspect/interceptor. Many long years ago - sometime in the latter half of the 1990's - I scanned in that diagram, redid the text and posted it online; in all the years since, I've never found another primary source on this, though the diagram I scanned way back when keeps popping up. Here you can see it in its full context.

http://www.aerospaceprojectsreview.com/blog/?p=1707