I got some furnace cement from INFAB, and today I am setting to work sticking these babies back together.
Luckily I've kept all the pieces together; otherwise this would be a nightmare job. As it is, its just glue & stick, glue & stick. The specific product I'm using is Quick Bond 3000, a high-duty air set mortar...maybe some kind of epoxy mixed with fire clay? I don't know. I do know that it adheres faster and better than I expected. It remains to be seem how well it will hold after firing. I wouldn't be surprised if those joints were far more fragile than the brick itself, in which case I'll either have to just keep pasting, or re-cast the blocks.
While I've got the bucket open, might as well repair a few softbrick, too:
Kiln maintenance isn't my favorite thing, but it's gotta be done.