Hi Josch,

"...In case of USNO B1.0 data, which are downloaded then only
the first method works, right?"

Yes.

One _can_ use B1.0 data in its original format, as described
at http://www.projectpluto.com/update8.htm#b1_from_hard_drive .
At present, though, even if you've got B1.0 stars _displayed_
from this source, and can right-click on them and such, you
can't "go to" them. Nobody's asked for that feature yet,
probably because B1.0 isn't widely distributed, and B1.0
numbers aren't widely used.

-- Bill