A quick update.
On the production server I uninstalled and installed roundcube and fetchmail, specifying the smecontribs repro in the examples above. However some packages were still pointing back to the stephdl repro so I reinstalled those as well. With hindsight perhaps I should have used the "--disablerepo=stephdl" command.
Anyway, this didn't resolve the missing packages on the backup so I've installed them by hand, so now when I run
/sbin/e-smith/audittools/newrpms
The items on the production box are noted on the backup, and both using either the smecontribs or epel repros.
Fingers crossed that both boxes should now the the same...
The one issue is that if I run a yum info command on the new roundcube and fetchmail, they are noted in Red. Do I need to explicitly or permanently enable the smecontibs repro with a command ?