Gen Con West (aka Pacific Encounters) 78 was held at the Villa Hotel, San Mateo, California from September 2-4, 1978. It was the third and final Gen Con West, followed by Pacificon in 1979. The D&D tournament was "The Dragon Crown".
The Villa Hotel, San Mateo, California, site of the Pacific Encounters gaming convention in 1978 (the hotel was closed in 2005).
"The Dragon Crown" was designed by Michael Mayeau and published by Judges Guild as the "Collectors Edition of the 1978 Pacific Encounters Contest Dungeon" (Mayeau would go on to write other adventures and supplements for Judges Guild).
JG 76 "The Dragon Crown" (1979) by Michael Mayeau. Cover illustration by Jennell Jaquays (a recreation of the original, which was temporarily lost in the mail).
In the scenario, the party inadvertently stumbles into a red dragon's lair. Rather than incinerating them, the dragon gives them four hours to retrieve a powerful magic item stolen by a nearby tribe of kobolds, the "Dragon Crown".
*the combination of a red dragon with a tribe of kobolds is also seen in module B5 "Horror on the Hill" (1983) by Douglas Niles
As with previous Gen Con tournament dungeons, the D&D tournament for Pacific Encounters 78 was run using OD&D + Greyhawk:
The Vol. I, II, III, and Greyhawk rules must be used. I realize the Advanced D&D is out, but it was not at the time this contest was designed, and was only newly out when it was run at Pacific Encounters.
Michael Mayeau, The Dragon Crown
Mayeau includes a list of tournament rules, such as bandaging wounds to recover 1-4 hit points (only possible once per day), ability score checks for opening secret doors (intelligence) and understanding traps (wisdom), and a system for critical hits and fumbles.
I haven't played or run "The Dragon Crown", although might consider doing so as a one shot. It could be used in a campaign for a low-level party, introduced as a seemingly abandoned cave while traveling in the wilderness.