Mike,
The "trapeze" and "pedestal" sights are the same thing. The G model only had the floor mounted flexible sight in the front cockpit. They did not have monocular sighting systems. The only one that did was the AH-64 PNVS testbed Cobra that had the nose replaced by an early PNVS mount and turret. That airframe is currently at Ft. Eustis, VA. The clear mounting in the nose is for the landing lights on 1966, 1967 and early 1968 birds. Mid-production 1968 and later birds had the landing light relocated to the fuselage underside and the clear nose painted over. I've seen plenty of pics where the lights were removed from the nose and the clear fairing was left as is. One that particularly comes to mind is "Satan 10" from the 235th AeroWeapons Company in Vietnam. Instead of nose landing lights, it just had a piece of plywood sealing the back of the light compartment that read "Satan 10".
There were a few night vision systems associated with the G model Cobra, particularly CONFICS and SMASH, but neither reached production and neither was a sighting system. The G simply never had helmet mounted sights. As for the deletion of the 40mm grenade launcher, it wasn't replaced until the entire turret was replaced with the M197 20mm cannon. The 20mm was a much more effective weapons system which allowed much greater standoff capability than either the minigun or the 40mm GL. Plenty of S (MOD) Cobras flew with the minigun/chunker combination until they were withdrawn from service.
Hope that helps!
Jon
Mel,
Yep, did a lot more work on this bird. It still has a lot of repairs needed, but its lookin pretty good at this point.