Apepa, I'm a bit sorry I brought up the landing gear issue, as I get it (now) that you were asking about the intended appearance of the triangles, not their intended function. But let's face it, if I didn't bring it up, the result would have been the same!![]()
Well, at least I've learned something new

But yeah, I'm trying to make a decision about how to model it. I always thought it was just a decal, but when I saw the close up shots I realised it looked more like the sort of trompe-l'œil they also used on the inboard of the starboard nacelle. I could either recreate the paint job or actually create an inset into the geometry, but I'd much rather the latter option, as having more corners to catch reflections and shadows almost always adds to the perceived realism of a CG object.