I was planning to re-build the ourdelta packages to use the upstream RPM package layout but I've decided to stick with re-building the percona packages as I've already done the work for that.
Anyway, in case it helps someone, here's how to rebuild the ourdelta packages from the SRPM:
rpmbuild --rebuild \
--define 'ourdelta 1' \
--define 'mysqlversion 5.0.87' \
--define 'elversion 5' \
--define 'patchset d10'