Some time ago, I upgrade my FreeBSD box to 7.1-RC2, but now I'd like to move to 7.2-RELEASE. I tried running

# uname -mrsi
FreeBSD 7.1-RC2 i386 GENERIC
# freebsd-update upgrade -r 7.2-RELEASE
Looking up update.FreeBSD.org mirrors... 3 mirrors found.
Fetching metadata signature for 7.1-RC2 from update4.FreeBSD.org... failed.
Fetching metadata signature for 7.1-RC2 from update5.FreeBSD.org... failed.
Fetching metadata signature for 7.1-RC2 from update2.FreeBSD.org... failed.
No mirrors remaining, giving up.

Substituting 7.1 for 7.2 gives the same error. Adding a --debug option shows the failure as being

fetch: http://update4.FreeBSD.org/7.1-RC2/i386/latest.ssl: Not Found

Is there any way to still do a binary upgrade of this system as the 7.1-RC* directories don't exist on http://update.freebsd.org anymore? Upgrading from source is an option, but I wanted to see if there was some way to salvage this installation.