This is N6356T, now N72FT I believe - not long after it came back to the USA after being in Europe with Charles Masefield
The February, 1975 Air Classics has a photo of this airplane on page 61 in the Reno '74 story. The photo caption states:
"A newcomer to Reno was Race #12, N6345T, a stock Mustang flown by Gerald Martin. This aircraft was an ex-RCAF machine and was almost stock. It had spent most of the 1960s in England where it was the mount of wealthy English pilots. While overseas it had the distinction of winning the King's Cup Air Race which is a handicap event that pitted Tiger Moths and Cessna 150s against the Mustang. Even with an amazing handicap, N6356T took the race without trouble. "