Anyway, to resurrect this topic, I recently redesigned my Modular Combat Carbine (a more detailed description can be found on the last post of page 15 of this topic) I created for a PMC story I started writing and, using shapes, blocked out "unneeded" areas on the mock-up FF rail system to make it look a little bit more accurate to the KAC URX II it's standing in for.
Here's one with an EOTech sight
Here's one sporting an ACOG with a small red dot optic attached. I used one of the shapes to cover up the rear BUIS and colored it white, then scaled the optic down slightly and sat it on top the ACOG.
And just for kicks, here's the shorter CQB-R version with an Aimpoint RDS.
The half cut-off PEQ-2 is intended as a mock
PEQ-15 laser module, BTW. And before anyone points it out, I left the magazine off on purpose because it looks more "encyclopedic" without it, like the weapon sitting on a display shelf (if that makes sense).