The first race to actually have a Cobra on the track for a "road racing event" was at Connellsville (August 25/26, 1962). The entry was by Ed Hugus and the Cobra is 2001....it broke in practice due to teething issues (overheating?) and did not race on the weekend.
"Hill Climb racing" Cobras seem to appear around mid-1963.
"Drag racing" Cobras seem to appear around early-mid 1963.
"Autocross, Slalom, Gymkhana, etc." Cobras seem to appear around the mid-later part of 1963.
There could possibly be earlier events, but newspaper articles, etc., only reported the top finishers for events.
From the "kranky Cobra Race History" ??
Riverside, Ca.-3/4/1962
csx2000-demo laps-Shelby American
Waterford Hills, Mich-SCCA Regional-8/25-26/1962
csx2002-demo laps by Ford Engineers/Test Drivers
Connellsville, Pa.-SCCA Regional-8/25-26/1962
#?-csx2001-DNR-practice laps only-Ed Hugus
Riverside, Ca.-3-Hour Invitational-10/12-14/1962
#98XP-csx2002-DNF-Bill Krause-broken rear hub
jim p