I see that there is ArtifactDeployer at https://github.com/jenkinsci/repository-connector-plugin/blob/master/src/main/java/org/jvnet/hudson/plugins/repositoryconnector/ArtifactDeployer.java
But for life of me can't figure out how to actually, manually upload an artifact to a Nexus repo ... I would hope/suspect there would be a Builder or Publisher that could do it.