In a nice archive dig NYRA has provided several videos of John Henry racing in NY from 1978-1979-1980-1981-1983-1984
youtube - NYRA page - John Henry race videos
They have about 20 of them up.
Video: Aqueduct Racetrack - 5/21/1978 his debut on a NY track in a $25k claiming race.
Video: Allowance - Saratoga Race Course - 8/8/1978 his Spa debut. Darby Creek Road set the track record in this race.
Video: Brighton Beach Handicap (G3) - Belmont Park - 9/7/1980
Video: Belmont Park - 9/22/1984 - Turf Classic (G1) this was his last appearance on a NY track.
One observation is that some of the race calls (compared to today) is frankly just poor at the finish.