As a long time Usenet user, I think you've come up with a very good solution. A few thoughts to add:
Come up with a mutually agreeable naming convention - the subject line for the posts doesn't have to be the same as the file names. Many groups that are using Usenet for storage obscure the name of the contents to remain "under the radar" - however this is considered poor netiquite in the Usenet community.
For those doing serious posting, you'll want to get a copy of PowerPost - it's the best Usenet posting tool for large groups of files. If you are just posting onesies and twosies, then posting abilities in Newsbin Pro or one of the other newreader programs will probably be just fine.
As soon as a collection is posted, use your newsreader program to create an NZB file of all the article numbers for the parts that were uploaded. (NZB file is similar to a torrent file).
This forum then becomes the place where you can post the NZB files along with a more descriptive list of the contents.
There's a secondary reason for posting the NZB file here in the forum. Whether you partition for a new usenet group or just commandeer an abandoned one, the newsgroup itself will become littered with spam in no time flat. Finding the articles you want will become a nightmare. But if posters add the NZB file to the forum here - no-one needs to even search the newsgroup headers for entries - and everyone is saved the headache of dealing with all the spam.
Note that almost all the reputable usenet providers follow DCMA guidelines and will remove any set of articles that a publisher says is theirs - so just as you already do here, you need to be ready to accept that some postings may be removed. Often times boards have a semi-formal way where forum members can report that they have found that a file has been DCMA removed so others do not waste time trying to access it. There's also a line of reasoning that you should NOT obscure the subject names in usenet posts if you will be keeping a cross reference between names and actual contents in your forum. Doing so could put you at risk of being accused of knowingly posting stuff that is not free and clear of copyright concerns. This community already seems to already take the high road on the topic, so I see no reason to try to hide names when posting. If an owner makes a fuss and has the usenet providers remove the articles, it's not as if you were purposely trying to get away with something illegal.
And yes - I have a vested interest in all this. I've been using Usenet for well over 10 years, and running a Usenet recommendation and FAQ site for nearly as long. I've built some comparison tables for providers, different newsreaders, insights into who does what in the industry, who's feeding which sites, etc. www.newsgroupservers.net
And for those concerned with ISP's tracking your IP, you can get real anonymity by doing everything through a VPN account. I have a website about that too: vpncompanyreviews.net
I'm not here to shill them, so I won't say anything more about it. Just a lurker who wanted to throw in his two cents worth.
Keep this stuff alive guys!
Bruce of the Anchodudes
