No, I was thinking of FTP, but I was probably off the mark anyway: I'd noticed that FTP was mentioned in the RFCs and surrounding discussions long before RFC 79

No, I was thinking of FTP, but I was probably off the mark anyway: I'd noticed that FTP was mentioned in the RFCs and surrounding discussions long before RFC 793, and that it seemed to be behaving like a point-to-point network, but it hadn't occurred to me that it might have just been using an ancestor of TCP/IP -- some variant of the "Host protocol" perhaps? Hard to get the full context, it was before my time: my beard may be grey now, but I'm not that old.