War History Online has posted some interesting photos of Sherman tanks converted into civilian work machines after the war.  Most of these pictures show vehicles in which the turret and upper hull were removed and then used as the basis of a heavy vehicle for construction, forestry or mining.  Some of the pictures show rather extensive modification to the hulls, including at least one example where a fourth suspension station was added (see picture to the left.)  A couple photos also show vehicles based on M3/M5 light tanks, although this is not noted in the original article.  The three page gallery may be viewed here.