Check /var/cache/apt/archives, that's one way.
Second method is to edit /home/user/.osso/hildon-application-manager
and change clean-after-install from 1 to 0 then check /home/user/MyDocs/.apt-archive-cache/ for the debs.
Third method (repacking the files into debs), is to download and install dpkg-repack from the SDK repos, however since docpurge purges the documents you'll get some problems while repacking.