two shades of pea green, light and dark
http://img156.imageshack.us/img156/3967/mackdump1bmm8.jpg
http://img156.imageshack.us/img156/3636/mackdump1aah9.jpg
the bases, different rear axle covers and different style tires
http://img255.imageshack.us/img255/1105/mackdump1cmd0.jpg
different rear clip, possibly reversed and a better picture of the tires
http://img368.imageshack.us/img368/8193/mackdump1hxe2.jpg
a short brace near axle of the dump, small and large axle holders on the dumper
http://img153.imageshack.us/img153/7384/mackdump1iam5.jpg
a different mack dump than the above models with another shot of the brace and axle holders
http://img466.imageshack.us/img466/5772/mackdumpsf28rearbrace1fb6.jpg

I have 2 of these, both shades but one has open cast steps, the other closed cast steps.I have a childhood memory of seeing these in store in metallic green but have seen no mention of this variation in collector circles, perhaps its my overactive imagination :confused:
I saw the real 1:1 deal once (1988) in a wreckers yard - here´s my pic
http://i38.photobucket.com/albums/e113/SMS369/MackDumper.jpg

a metallic green dump would have nice :)
i like you 1:1 pictures, it looks enormous :)