A good and simple way to do this would be to create a file that matches the draft filename without the version number (would this be that tombstone thingy you guys keep talking about?) and say something like "version 34 was submitted 2003-04-05" or "version 00 was deleted 1970-01-01"
You can find an implementation of that form of indexing I-Ds at http://www.potaroo.net/ietf/xids-ietf.html
Geoff