@gsgmfg@fosscad.io did it, the madman. In conjunction with a kind user from the Index's Lemmy instance, he was able to restore almost all of the data from /r/fosscad. There's a bit of a loss in images, but the text -- the oh-so-valuable advice and discourse -- is all there.
And the best part: it's federated between both of our instances. There are now not one but two copies of the data: one local to his instance and one local to mine.
Find it here: !ark@fosscad.io
Awesome work. I'm grateful it wasn't all lost. I'm so glad to be rid of that website/horrendous app. Lenny/Mlem will take some getting used to but it can't possibly be worse than the first party reddit client (rip Apollo)