Have to say the file is a little jankey, some bits accidentaly not mirrored etc, and its very fragile, so while yours is movie accurate, mine is slightly more buildable, however im a rookie MOCer (SECer? someone elses creation?) so many not me used to certain construction techniques.
It never helps that LDD can be very jankey when creating instructions. even though pieces blatantly connect to each other, LDD makes you create some very large pieces, and then you realise you have to add all the Technic pins!
Also the barrels for the engine coves don't actually connect to round 2x2 plates, square playes yes, but round, nope. (the Kragle was the solution MUHAHAHA!!)
Also, grey barrels and white velux roof windows pieces were pretty rare. Tamiya XF-19 sky grey, and X2 white (with some X-22 clear (gloss) over the top) worked great