It seems to me that the SDF truck pictured in the MLU Forum post I referenced is a Chevrolet 1543X2
comparing it with this picture from
http://www.mapleleafup.org/forums/showthread.php?t=12940 which I had overlooked.
It clearly has 10-stud rims which seem to correspond. So actually I should be able to answer my original question whether the SDF had trucks with 10-stud 16" rims...
Does anybody find mistakes in my identification of the truck or other considerations?