Dating cruchon emons
I think we can safely assume that the year was the year of manufacture.
It is not unheard of to find a compass without a case number, date or even a supplier name.
The other features such as a momentary bearing lock (button visible at about 8 o'clock on the outer edge of the case), transit lock and prism structure are as for the V.
The lower card is much less common and has an embossed aluminium dial that has been painted black, but this is the only major design change from the more common model VII.
The V has just a plain card without the Northern cardinal mark evident on later models and is shown on the left.