Deployment by Folder - alternatives?

[LisaG]

We are required to maintain output versions of reports for a period of time (30 days to a year).  We also have a "monthly final" of these reports which is archived elsewhere.

This works great except when we need to update a report.  The only way I have found to maintain these output versions is to deploy by the final folder and check "Keep the existing report specification versions".  We would like to be able to deploy single reports rather than complete folders.  It seems a bit risky to deploy large numbers of reports when we only want (and test) changes to a single report. 

I have tried moving these reports in a separate folder, and then opening and "saving as" the report in its proper location, but this always loses the old output versions.

Does anyone know of a method to deploy and maintain these output versions without deploying entire folders?

Thanks in advance,

Lisa