I just had a look at the ModeShape product branch - it doesn't seem to have the Javadoc plugin integrated (only the community version does). So I've opened & linked another BZ for this https://bugzilla.redhat.com/show_bug.cgi?id=1063426 which I can fix once it's approved.
Verified for sanity. Directory structure looks the same as when generated from sources downloaded from CSP.