Hi David,
As Oliver indicated, "Go To... User-Added Dataset... MPC
Observatories" has no real meaning except in geographic mode.
That function does work in terms of "going to", i.e., recentering
the chart, on a given part of the sky. I suppose extending it
to include the idea of "reset my viewpoint to a given location"
might be a sensible extension. Though as I'll explain, it's
not really necessary; there are easier ways to go about it.
You _can_, while in the usual "star charting" mode, use
"Settings... Location", then "Enter Location Name", and
enter (say) "E14" to reset your viewpoint to that of any MPC
station. Or, when in geographic mode, you can click on
"Go To... Enter Location Name", and again enter "E14"
to have the chart recenter on that MPC station. (Note:
this is case-sensitive.)
I just checked, and the list you downloaded was last
updated a couple of months ago; some new MPC stations
have been added since then. Revisit
http://www.projectpluto.com/extras.htm#MPC_stations
and download that file again, and you'll be all set.
Also, don't put these in the Text folder; all files for
download from the Web site are intended to go directly into
Guide's own folder. (After all, some people haven't installed
Guide to the hard drive; they don't even _have_ a Text folder.)
"...The zip file contains 4 files but Guide 8 seems to only
need 2 (.TDF and .DAT files)." True. The .DDF ("Deutsche
Definition File"; German speakers will please excuse the
mixed "Deutlish") enables display of MPC stations in German.
The .CPP file is the C++ source code used to convert the
MPC locations, expressed in terms of parallax constants,
into latitude/longitude/altitude form. Somebody asked me
for this a long time ago... don't remember who it was. Most
people can safely ignore both files.
-- Bill