[servicepub (RIP)]

Hi Rob,
Interesting points. I suspect that, once a contract is let then DND would set aside blocks of numbers in advance of actual receipt. I know for a fact that this occurred with the 1938 and 1939 purchases of 15cwt trucks from GM and Ford, respectively, even though the Fords were mostly delivered in 1940 they are all numbered in the '39' prefix. Still unknown is whether DND stuck with calendar year (Jan-Dec) or fiscal year (Apr-Mar).
As to finding vehicles interspersed as you described, contracts in the early days were flying fast and furious and many were amended over the course of their term to increase numbers. I can see where a contract for xx vehicles would have DND set aside a block of numbers, then another contract let for a different vehicle (with their numbers reserved) and then the first contract amended to increase quantities with a resulting block of numbers. At the end of the day you had this small group stuck in the middle of a larger block.
At no time were numbers allocated to regions (or Military Districts) for allocation and these were all controlled out of Ottawa.
I know that in my SP work I have a block of 100 ISBN numbers and I will set aside an ISBN number when I decide to take on a project. However, later numbers may be published first and the numbers cannot be used to identify the publications sequentially. I suspect that something similar may have occurred with vehicle production.
In any event, the article is based on original documents which show intent if not practice.