I've 'refined' the walls of the 3D model of USS Sulaco's hangar and adjusted the number of 'side-support' structures to match the film set. I have been using the "Aliens - Definitive Edition" DVD as my main source of information for the hangar layout., as it has multiple views of the hangar and the UD-4L 'Cheyenne' Dropship.
The 3D model hangar is still far 'perfect', but it starting to get the look of the USS Sulaco's hangar. I've added a 'basic' crane in the hangar and have 'loosely' positioned the crane components. The four main vertical components that run down the Dropship's centre fuselage, I have no idea what their exact purpose is; fuel transfer, grapple, who knows. I'll model these better after watching the film, again :)
I have also discovered that in the pressure chamber that is under the primary Dropship, it has at least three supports that hold the Dropship in place prior to launch. Two under the forward weapon pylons, a third at the rear of the craft. Must remember to model these