It turns out to be surprisingly easy to create a basic puppet client package.

The steps involved are:

Install the ruby & facter package for the desired architecture (i586 = 32bit, x86_64 = 64bit).
Install the puppet src.rpm
Move the puppet-2.6.7.tar.gz file to /usr/src/packages/SOURCES

Edit the puppet.spec file located in /usr/src/package/SPECS, change the lines Version and Release so that the read:

Version: 2.6.7  
Release: 1.2

rebuild the puppet package with the following command:

 rpmbuild -ba puppet.spec

Install the puppet.arch.rpm found in /usr/src/packages/RPMS/<arch>/