The original APC body has to be carefully trimmed across the front and at the rear, the castings then fit over the hull sides. I don't have to split the chassis from the top, so no drilling of rivets. The jerrycans at the rear and on top disguise some of the joins in the castings. The result is a fit which is very much how Dinky would have done it.
An idea for the future would be to make tin tents in the style of Dinky "Tilts" to fit around the model as shown below.