This went almost completely flawlessly.   Some ugly notes i took while following this howto below.

  - Install the dependancies before enabling the testing repo. Otherwise a testing will install httpd-2.2.8 rather then the normal 2.2.3

Install rpmdevtools
  - run rpmdev-setuptree
  - append the following to your .rpmmacros
     - %packager       Your Name <your@email.addresss>
     - %vendor         Your Company

  - The following line has a typo.  'python-kerberos' should be 'python-kerberos*'.
    rpmbuild --rebuild TurboGears-1.0.3.2-7.el5ipa.src.rpm krb5-server-ldap-1.6.1-26.el5ipa.src.rpm python-kerberos python-tgexpandingformwidget-0.1.3-5.el5ipa.src.rpm mod_nss-1.0.3-5.el5ipa.src.rpm
  - Delete those extra garbage rpms.   rm ../rpmbuild/RPMS/x86_64/*debuginfo*
  - To install the krb and python packages created in the repo, yum --nogpgcheck install ~builder/rpmbuild/RPMS/*/*.rpm
 
  Building IPA
cd srcbuild
mkdir done
mv TurboGears-1.0.3.2-7.el5ipa.src.rpm done/
mv krb5-server-ldap-1.6.1-26.el5ipa.src.rpm done/
mv python-kerberos-1.0-5.el5ipa.src.rpm done/
mv python-tgexpandingformwidget-0.1.3-5.el5ipa.src.rpm done/
mv mod_nss-1.0.3-5.el5ipa.src.rpm done/

rpm -Uvh ipa-1.0.0-23.el5ipa.src.rpm
mv ipa-1.0.0-23.el5ipa.src.rpm done/

cd ../rpmbuild/SPECS/
mv ipa.spec ipa.spec.save
sed -e "s/redhat-ds/centos-ds/g" ipa.spec.save > ipa.spec
rpmbuild -bb ipa.spec

  Building the rest.
cd ~/srcbuild
rpmbuild --rebuild *.rpm