I know of at least two hollow-state direct-conversion receivers in QST:
May, 1961 (more than 50 years ago!) W2WBI described a "T.R.F. Receiver" for 80 and 40 with a balanced detector. RF stage, pair of pentagrids, VFO, audio amp. Nice job, but for that many tubes you could have a small band-imaging superhet. Although the term "direct conversion" is not used in the article, it is clearly that kind of receiver.
July, 1973, shows "The 80 Meter Pebble Pulverizer" by W1CER and W1NPG. A complete QRP CW transceiver for 80 using tubes. 6GX6 is the detector.
73 de Jim, N2EY