If you want a supportive opinion, Nigel -
I think you (or someone) should just add Silbaby as a site. Then all the photos, comments and forum threads can be collected together for easy access.
After all. I know we don't want loads of 'possibles' on TMA but this one has already been debated by people on here who clearly have detailed local knowledge of the area, and who don't routinely suggest every molehill in the landscape as a Genuine Prehistoric Site.
So just do it (I say).
Modern Antiquarians are allowed to (re)discover things.