[pgsql-pkg-debian] 9.2 on Debian 5.0 (Lenny)?

Hi,

I'm trying to upgrade an old machine we have currently on Debian 5.0
(Lenny) and PG 8.3 (yes, I know it's ancient, but the software is that
good it just keeps on working without problems).

Perusing https://apt.postgresql.org/pub/repos/apt/dists/lenny-pgdg/
seems to indicate that 9.2 should be available, but trying to install
it results in errors:

colin@lb-replica:~$ sudo apt-get install postgresql-9.2
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package postgresql-9.2 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
E: Package postgresql-9.2 has no installation candidate
colin@lb-replica:~$


This is a different error than if the package is simply not available:

colin@lb-replica:~$ sudo apt-get install postgresql-9.3
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package postgresql-9.3
colin@lb-replica:~$


Trying to install just "postgresql" results in a similar error message:

colin@lb-replica:~$ sudo apt-get install postgresql
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  postgresql: Depends: postgresql-9.2 but it is not installable
E: Broken packages
colin@lb-replica:~$


My relevant APT files are as follows:

colin@lb-replica:~$ more /etc/apt/sources.list
deb http://archive.debian.org/debian/ lenny main contrib non-free
colin@lb-replica:~$ more /etc/apt/sources.list.d/pgdg.list
deb http://apt.postgresql.org/pub/repos/apt/ lenny-pgdg main


I can just upgrade to 9.1 but it would be very nice to upgrade as far
as we can without upgrading the OS.

Thanks!

/Colin