Interesting - but you are managing the junit reports for each build. What if older builds or specific builds are deleted from Jenkins?
It seems like, even if there isn't a Jenkins plugin for Junit History, that it would be possible to mimic it.
How about just using the Junit results from the previous builds located in ${JENKINS-HOME}/jobs/${YOUR-JOB}/builds.
If junitth requires a specific directory naming scheme, I guess it would mean copying re-creating the existing build directory tree since buildid is a sym link to the build dir which has a number of the daystamp. This would be possible with some scripting code.
