They are out there. I am restoring TWO Admiral 24A12s as we speak. Both in superb shape, no cracks. One is up and running, thanks to Henri, aka TVDude1, as he troubleshooted it after I recapped it.
I literally bought them about 4 weeks apart. Couldn't pass up the second one, it was that good. Now, I have a Mid and a Late Production Chassis each, and, it's interesting to rebuild them side by side.