Ubuntu Installation :: Finding Packages That Are Not On An LTS Point Release CD?

A while ago I posted this thread, with no responses:[URL].. I deploy into an environment that for "security" reasons cannot be kept up to date with wherever the ubuntu archive is up to (with awareness that this is avoiding security updates...). It is a sealed system not connected to the internet. I'm working with the 8.04.1 LTS, and my customer is in an 'if it ain't broke don't change it' frame of mind w.r.t. moving to 8.04.4. My main problem comes in two variations: 1. Some packages my runtime system depends on are not distributed on the 8.04.1 DVD, but were available in the full ubuntu archive at the time of the point release (and still are, in an up-to-date form). My concern is that if I take the 8.04.4-ish version of a package it will not work correctly with an otherwise 8.04.1 system. In general I am expecting that it *might*, and the versioned dependencies it has on other packages will be loose enough. 2. Some packages my build system (which produces what I put onto the runtime system) depend on are also not on the DVD. So almost a repeat of 1 above, except that I am generally running afoul of strictly-versioned dependencies (the -dev version of a lib package depends on the matching lib package having exactly the same version). If the non-dev lib package is on the DVD, but is not the same version as the -dev package I have from an archive mirror taken just before the 8.04.1 release, I believe I'm screwed?

So my two questions are: a. Is there such a thing as a copy of the full ubuntu archive taken at the exact time the 8.04.1 LTS was released? I think that would solve most of my problems.