We're setting up a local mirror for our site which will probably include
updates. We have different machines at various different update levels
(4.3, 4.7, 5.1, 5.2, 5.3 etc.) and I've setup the mirror for those from
the contents of the DVD ISOs.

For the updates (which I'm assuming includes errata and fastbugs)on
ftp.scientificlinux.org it looks like, for example:

ftp://ftp.scientificlinux.org/linux/scientific/40rolling/i386/errata/SL/RPMS/
- contains all updates from the release of 4.8 to the present

ftp://ftp.scientificlinux.org/linux/scientific/48/i386/errata/SL/RPMS/ -
is currently exactly the same as the above (until 4.9 is released)

ftp://ftp.scientificlinux.org/linux/scientific/43/i386/errata/SL/RPMS/ -
contains all updates from the release of 4.3 up to the present (ie. it's
a superset of the 40rolling and 48 errata directories)

ftp://ftp.scientificlinux.org/linux/scientific/47/i386/errata/SL/RPMS/ -
contains all updates from the release of 4.7 -> present (ie. it's a
superset of the 40rolling and 48 errata directories but a subset of the
43 directory)

Is this understanding correct? If yes then I plan to sync the updates
for the earliest version we have (4.3 for the 4x series) and use that
directory for updates for all machines (4.7, 4.8, 4.9?) - will this work?

Thanks

Tim