Yeah, don't post there. A group that would welcome images illustrating "how to convert a Pentax 645 film insert from 220 to 120" (to use your example). yet would insist that those illustrations be scans of analog prints, is being administered too foolishly to waste time on. That's absurd.
There are ways around this - it is a discussion group after all. Follow their rules insofar as they say don't post the digital images to their pool. Instead post to one of your own sets, then post a link to it to the flickr group. You didn't violate the rules by posting a digitally acquired image to their pool, you only posted a link to the images. Better yet, set up a blog (wordpress or blogger come to mind), write an article, and post images with it. Then post a link here so those of us who are interested can find the info.
Shoot more film.
There are eight ways to put a slide into a projector tray. Seven of them are wrong.