Larry
The DML Dragon kit comes with 2 different covers, one with an "arrow" piece on the face, the other just flat but both have the same external dimensions.
For placement on the hull - the bottom of the cover is exactly level with the hull sponson bottoms (bottoms of the horizontal arm of a "T" ) and 29mm right of the left bottom corner. The top of the cover is 9.5mm from the top of the glacis.
xxx
/
xx /
x / xxxxxxx|xx|
/____29___|__|
xxxxxx|
xxxxxx|
xxxxxx|
Hope you can understand this diagram. Ignore the x's (they are there to keep measurements right). The green is the hatch cover, the red the hull and the blue the sponson bottom extended to the bottom of the hatch to show the measurement.
Oh yeah, I think Bill means mm, not cm and then his measurements will tbe fine. Must be tired eh Bill.