Multi-ejector exhausts with circular exit pipes were never fitted, on the production line, to Merlin-engined Spitfires; they had only the "fishtails."
Post-war (June 1946) they were fitted to the Griffon-engined 14, 18, 19 & 20-series, so, by default, found their way onto some still-extant Merlin airframes, but you'll need a clarifying photo, to be absolutely certain.
Edgar