[Nexus] Upload of pom and jars without using Maven to re-create them

I want to upload the commons-daemon 1.0.5 jars from the binary
release, as the Maven files were not uploaded at the time.

I extracted the jars (binary, source, javadoc) and pom, createdt the
associated hashes and sigs, and I'd now like to upload them to a
staging directory.

However Nexus does not seem to make this easy or even possible.

I tried creating a bundle using repository:bundle-pack (having first
copied the files to my local repo), however Nexus appears to have hung
trying to upload the bundle. The blue uploading bar is still going
after about 5 minutes.

Previously I tried uploading individual artifacts but that was not successful.
It does not help that the artifacts window is so small that one can
only see about 3 lines without scrolling.
But it's also no clear whether one has to upload hashes or not, and I
kept getting messages about duplicate artifacts and incorrect MD5 and
sigs.

Has anyone successfully uploaded ?