Despite not liking the concept and format of Facebook, I post rather too much there..One aspect that works is the ease of posting photos...It's a pain in the **** on Braveheart or whatever it's called...but anyway, I've been tidying and sorting my tins following my last trip to England and collection of two years worth of eBay purchases so I've been able to make some comparison photos. Although pre-war Norton toolkits seem to have included the half round Romac 'Half-a-Crown' repair outfit, it seems likely that by 1940, they had switched to rectangular Dunlop tins (as used by Royal Enfield with the WD/C). There are a number of variations on the Dunlop tins that turn up, but the red and yellow wartime version seems to be the earliest of this style...Crucially, the lettering should be yellow on red, not black lettering and the side printing must be present. It would seem that the black lettering and plain sides were a 1950s practice.
This is the definitive 1939 Norton toolkit image..Queen Victoria's Rifles in August 1939.The Romac tin is clearly visible.
The rectangular Dunlop tin also appears in the initial Royal Enfield WD/C illustrations.
Again an early-war Norton example...
I suspect that either a Romac or a Dunlop outfit could be correct for BEF and early-war applications. To the War Office, the reference LV6.MT6/16287 was the important aspect and manufacturer was not relevant.