The elongated Wilkinson cartouche panel present on this example is often referred to by collectors as the “Masonic” panel. Although Wilkinson later reused this decorative cartouche on presentation and post-war knives, its earliest appearance in relation to the Fairbairn–Sykes is widely believed within collector circles to derive from a small early batch of Type I knives associated with William Ewart Fairbairn himself. While no surviving factory documentation definitively confirms this special commission, long-panel examples of this type are documented on early Second Pattern knives and are considered significantly scarcer than the standard wartime Wilkinson stamp. Unlike later presentation pieces, early Type I examples display correct wartime construction, finish and scabbard configuration consistent with initial production.
The elastic-retention scabbard format was introduced at the commencement of Second Pattern production, replacing the earlier First Pattern snap-fastener design. Elastic straps proved prone to deterioration in active service, and period field replacements are frequently encountered on genuine wartime examples, particularly on early Type I knives from this transitional phase of manufacture.