Are you only interested in Rubus species in exchange? I can certainly order species online (although with a collection as large as yours, you probably have most everything!). Or if you have interest in non-Rubus species, I could collect some of our local edible wild berries (mainly Vaccinium uliginosum (bláber / bog bilberry), Vaccinium myrtillus (aðalbláber / bilberry), Empetrum nigrum (krækiber / crowberry); there's a couple others (hrútaber / stone bramble, jarðarber / wild strawberries, skollaber / dwarf cornel), but they're not common). And some Ribes species, but they're only semi-wild. And ever common rowan berries, but they're not great, even when processed right
Everyone's favourites are usually the bláber and krækiber species. The bláber species might be hard to find this time of year, but there's probably a few hanging onto plants. Crowberries should be abundant.
Hmm, now that I think of it... hrútaber / stone bramble is a Rubus. R. saxatilis. But I doubt I could find any this time of year. I always think of them as kind of insignificant, I've never found a lot of berries in one location. But they'd probably do better in cultivation than the wild.