Worked this time. I probably did not wait long enough the first time.
I think the library format is unclear, compared to yahoo groups. The file link is deeply embedded in the post/ comments. It would be much better to have a catalogue of files that could be sorted by date or name, separate from all the chat etc, with just a description of the file. Does dabble allow this?
Yahoo Groups are lagging behind the modern best-practice forums; and it bombards you with adverts. The modern trend is embedding pictures within forum text, and whatever your hobby that's what people do. And newspapers have done it since 1609!
But good old Google are getting remarkably good at searching for and grouping pictures. Using Chrome hover over a picture and try the right-click "Search Google for Image" - you might be quite amazed how Google can 'group' pictures together. In other words the (old) Yahoo process of just seeing files in one place, is not necessary anymore.
Regarding WW Potters, here is one I built earlier - Paul Fisher's Lynx 14 design of a pocket cruiser being launched at the HBBR 2015 Thames Raid.
PS I've never posted this picture before so Google won't find it yet, but in a week or so it might, because they literally trawl the whole of the Internet.