John,
Yea... the only systems in the Honorverse to which corresponding stars in the real world are known are Sol and Beowulf. For the rest, it is like trying to find the address of your new friend who goes by the name Snake who lives in an unfamiliar part of town, knowing only his nickname and maybe the color of his house. Unless hidden someplace in a buried reference, there are no references to real world names or other designations which could then be used to lookup the star and get the details. There may or may not be something roughly corresponding, such as a star at the distance specified for Manticore which is a binary pair of roughly the correct spectral classes, but I can guarantee you that it would be pure coincidence and would still not be Manticore in even the remotest of ways.
As for your WAG... and the rest of your thinking in that paragraph, I can guarantee that the number of stars which would match would be much less than you think. See my original reply regarding the triangle which would be used to create the cone, and you will see why. But a simple search of the Hipparcos data set for stars with a parallax between 6.21 and 6.87 milliarcseconds (e.g. stars within a shell ranging from 475 to 525ly), which are multiple stars, with a spectral class roughly around G0, we only get 164 stars. And it should be noted that the number of systems is more like half of that number (not all stars came up with their companions... for example, if one had a K or M class companion, only one of the pair would show up). But this is a pretty thick shell of 50ly. If we instead drop it to 6.21 to 6.52 milliarcsecs (512.5 +/- 12.5 ly), which is still generous, this drops to roughly a dozen systems, all of which could be eliminated for reasons listed in my original reply.
Now, even if we knew the ID for Manticore A/B, we still would not be able to necessarily ID and find how to place the other stars, since a 2D map loses details in the projection from 3D. In effect, the projection is a lossy form of compression. The only way we would really be able to do the 3D map is if between David and BuNine, they had produced a table such as
this one, and then assigned names for use in-story. Indeed, were I to be deciding to create a story-verse as David did back when he started the Honorverse, I would be going to something like the Hipparchus or Gaia datasets, picking stars, and then computing the figures to use, also accounting for motion since we are talking a significant enough time ... I actually still have the F77 code which would allow me to do that burned onto a CD (which I transferred off of 2400ft magtapes over 2 decades ago, roughly a decade after I had transferred them from their original punchcards), though if I wanted the graphics output, I would have to rewrite those sections of the code. And I would get back the results in seconds, instead of minutes (or longer if the mainframe decided to glitch on my JCL deck) LOL