Thank you everyone for your input!
I have been doing night shifts recently, hence I did not have time to work on my model until the past few days.
The wings do look small. I have enlarged the wings on the L side of the model, as you can see below:
DSC_0118 by The Horned, on Flickr
(mind the dirty floor! I apologise for the poor picture quality, I don't have a photography studio like some of you lot!
I have increased the wing size on the left side by 3 studs, offsetting the lower wing into the engine 'slope' by a stud for a net gain of 2 studs in length, which appears more to scale now. I have also increased the width where the lower wing attaches to the engine slope to 5 studs from 4, which also looks according to scale from the reference pictures. I have thus correspondingly reduced the slope on the front side to 4 studs, as you can see on the right wing, which remained unchanged (this is a bit tricky to see, but you can clearly see that the new left wing i now thicker than the original right wing.
Addit: the left wing is now 14 studs in length (15, if you include the row of studs under the engine, vs 12 for the original right side. The widths remain the same. I tried to adjust the engine slopes, making them shorter, but I couldn't at this point, gaps start to appear which I can't fill. I'll keep on working on this. The left wing looks better in this regard as well.
As for the lower wing, I have reduced its width respectively to 4 studs from the original 5, as you can see.
I think this looks much better, your feedback will be much appreciated! Note, its still not complete, for example, it looks like I need to shorten the length of the guns of the lower wings etc.
PS:
I will take profile shots soon, when I have time and when the daytime lighting is good (as it had also been very cloudy and rainy over the past 1-2 weeks here in Brisbane, Oz).
Interestingly, I note that there is a noticeable gap between the upper and lower wings when they are closed, between the left and right sides (ie, when viewing the 10240 from the front, there is a larger gap on the left side compared with the right) even in the original 10240. This had also affected my MOC as well, as you will soon see!
True that, I'm somewhat torn between going all the way black, or making it more accurate with the DBG. We'll see!