There are several versions of the DND ARMY fire extinguishers. The ones ahown are my favorite. You can also find them stamped on the edge of the top, as well as find the DND ARMY on the label at the top.
I have also seen them with CPR on the top, so it looks like pyrene would custom make them for companies or departments.
Seems to me I made a thread on extinguishers about a decade back. Found it here:
http://www.mapleleafup.net/forums/sh...highlight=fire
I suppose a civilian extinguisher would be fine, but not one with insurance company markings on the label, which are quite common.
My favorite surplus yard still has dozens and dozens of these extinguishers, and not all are DND marked.