It looks like Transformerland does a brisk trade in incomplete/broken figures, including a lot of BW stuff. And apparently they often have a lot of bits and pieces in their warehouse that aren't listed on their storefront, from what I hear. It might be worth taking a look at their site and/or dropping them an email.
They've been around forever and I've never heard anything bad about them, but I've never actually done business with them myself, either, so take that with a grain of salt.
Just an update (with good news) while cleaning up I found Depth Charger's Energon sword. Somehow it got in a pile of old reports that was 6 inches deep.