I think to get a total of seven American systems you have to either include the LM
or (and this is a bit of a stretch IMO) put the Titan III-Gemini B system on the list..I can't think of any other options.
The later was the combination that was supposed to be used for the Manned Orbiting Laboratory programme. It never flew crewed because the programme got cancelled but there was one successful unmanned test flight of the whole stack in 1966.
https://en.wikipedia.org/wiki/Manned...ing_Laboratory
I'd say the X-15 only gets one tick - the upgraded version was, I think, very much a low level
High Speed machine..
Agree with Vostok/Voskhod/Soyuz for the Soviet types