As much as rebuilding old builds would be nice. What I am really interested in is slowing down the rate at which I get bad SNAPSHOTS. Bad SNAPSHOTs break my builds, cause my developers to waste time identifying it was not their change, prevents them from doing additional work, and additional bad stuff. The given example with a loooot of jars to archive also has a lot of continuous integration going with those SNAPSHOTS. Without any quality controls in place it also has a loooot of continuous breakage. I want to find some imaginary happy place dubbed continuous quality where I have all the benefits of continuous integration without all the detriments of continuous breakage.
What I would like to be able to do is run a bunch of tests against a SNAPSHOT (and its transitive SNAPSHOT dependencies) first before I hand it over to developers or continuous integration builds.
The idea would be to combine this feature with the jenkins maven repository plugin. That plugin as you maybe aware allows you to use another build as a maven repository. With that in place I could make one build pull down new SNAPSHOTS integrate it with my code and then run all my tests against the result, call it an acceptance build. I might keep a few of these builds around but not many. Then my developers, and my CI builds would use the last successful acceptance build as the maven repository they go to for SNAPSHOTs.
This puts one build of latency between me and my SNAPSHOTs dependencys for continuous integration. Not a bad price to pay for eliminating most of my breakages through dependencies.
That could really be a loooot of jars to archive. Plus - if I understand you correctly - you not only want the ability to archive the snapshot, but also the rebuild based on the archived artifacts instead of the ones from the maven repository, right?
IMHO, this is not very likely to be implemented (unless you do it yourself and created a pull request) and also to be honest not a very desirable feature, too. This is basically working against everything what snapshots are supposed to be. If you're really concerned about reproducability of builds, you should only use released versions!
And BTW: you can track which snapshots were used for old builds by checking Jenkins' fingerprints.