If "an establishment" had say 50 rifles and 50 bayonets which had to allocated to 50 positions/places on racks in an armoury and then the rifle, bayonet and position allocated an identification number, I would start at number one without giving too much thought to the matter, if I was asked to do the job. Would it be considered "normal practice" to mark the first position in an armoury rack with anything other than number one? If there were say, for example, 50 rifles and 50 bayonets with a corresponding 50 positions in the rack, if the first position on the rack was numbered up as 851, and the corresponding rifle and bayonet marked with that number, then the 50th and last bayonet would be 901. The alternative is that the Officer Training Corps had a large number of rifles and bayonets if numbering started at number one.