A Global War era North American terramobile.
A terramobile is a self-propelled armored vehicle, usually with a mounted cannon and one or more machine guns. During the Global War, terramobiles manufactured in the Confederation of North America were shipped to North American bases in Iceland, where they were "stolen" by North American soldiers disguised as Icelandic fisherman, and brought on board waiting British warships to be transported to Great Britain.
It is likely that terramobiles were widely used by all of the combatants in the Global War, though Sobel does not say so.
Sobel's source for the "stolen" North American terramobiles is Hugh Devenny's War and Men: Politics in North America, 1943-1952 (New York, 1955).