Apparently I got a bad copy of RPM... because here's what the darned thing's giving me now:

root@slax:/# /usr/lib/rpm/rpmdb_dump Packages-ORIG | /usr/bin/db_load Packages
-bash: /usr/bin/db_load: No such file or directory
db_dump: open: Packages-ORIG: No such file or directory
root@slax:/# rpm --rebuilddb -vv
/usr/lib/rpm/rpmd: error while loading shared libraries: libelf.so.0: cannot open shared object file: No such file or directory
root@slax:/#