100504 was one of the 144 aircraft ordered as Mk.4B and delivered to the RCAF on June 28, 1955. Sometime in its existence the aircraft was one of 50 Mk.4As and Mk.4Bs that were converted to Mk.5, and it was listed as Mk.5D when the aircraft was reserialed from RCAF 18504 to CAF 100504.

Beside the 50 conversions there were also 329 aircraft produced from the outset to Mk.5 standards, 53 being delivered to the Belgian AF. Typical for the Mk.3 and Mk.4, the production Mk.5 had no ventral weapons pack. On this Mk.4B conversion the eight 0.5 in (12.7 mm) guns have not been removed.

The Mk.5 had a 6 ft (1.83 m) increase in wing span and had the tailplane also extended. While the Mk.4 had an elevator that spanned the entire tailplane, as visible in the photo on the Mk.5 the extended tailplane had not an extended elevator. View also photo 9456 and the History Brief .