Yea, no one sells an exact repro, the present day ones have too many buckles and are all rubber (But there were 5 buckle boots produced read below) except for the one you pointed out. But even WPG one's aren't totally correct either they have the buckles and the canvas upper, but they are missing the high rubber lip that comes up around the base of the boot.
Here is another picture of what they look like
In 1941 LaCross received a contract from the U.S. Army to produce 43,200 pairs of Arctic, rubbertop overshoes. It was the first of several government contracts that La Crosse Rubber Mills would fulfill over the coming years. During World War II it produced jungle rubber footwear, hip boots, four-buckle overshoes, tennis shoes, and rubbers for use by military personnel. When the war ended in 1945, the company promised all returning veterans who had worked for the company that they would either get their old jobs back or be hired for even better ones.
Very Large picture of the hundreds of boots
http://www.archives.gov/research/africa ... ii-037.jpg
Here is more information, which supports a 5 buckle and a 4 buckle bookt
Several versions of World War II overshoes were manufactured, one with a side pleat in the upper panels, a second that employed five buckles, and a third version, the “Overshoes, Arctic (Canvas Top)” issued during the middle of World War II with no pleats and four buckles (Lewis 1993:154). The overshoes accessioned as CILHI 2001-126-A-03 also have no side pleats present and they bear evidence of a four-buckle configuration, thus they are consistent with Overshoes, Arctic (Canvas Top
http://www.jpac.pacom.mil/Downloads/WWI ... 01-126.pdf