Silencers and rifles Levelup 1

Hi,
I am progressing my MO across Levelup 1 and a kind NCP volunteered his Crysis assault rifle for my MO to test..
I don't recall now that I am away from my PC the first part of its name but the Crysis takes NATO ammo, likewise its under barrel grenade Launcher. Its sight is an Acog, and in Esc S weapons there is a dedicated silencer, but when applied to the rifle does not attach to it.
The silencer modelling looks new, whereas the crysis assault rifle has been a stalwart for the game. Is there another upgrade available to fit this silencer/suppressor please?
I think it might be worthwhile unless it has already been done to match the attachments available to firearms available to find out which attachments fit which firearms so when it comes to purchasing them from dealers, players don't have to waste funds experimenting.
I used to have a list which I shared with some members, so if there isn't one, I can search my old storage but I think I may have deleted them. So if any Forum members have a copy, perhaps it can make the basis of a list, available to any player including me.please, as the e-weaponry side of things is also enjoyable. Thanks and Regards, TrueB