Okay, so after trying to work with the rev sources you gave me, I noticed that its code has been almost completely overhauled. Most notably in the HUD functions. It is completely different, so I can't really replicate the way they rearranged the ammo icons into multiple rows. (Same issue with Cecil's overhaul.)
The attempt to separate the secondary fire from use and Netricsa has been half successful. Finally gotten rid of that annoying bug where you have to wait a moment after firing off a secondary shot, otherwise it'll just keep doing it even though you're pressing the primary. But now the grenade's and cannon's secondaries can't be charged anymore. And judging by traces left for a scrapped idea (grenade spam fire), that might be unfixable. It also broke sniper zooming, making the player unable to fire or switch weapons. Haven't tried the controls yet.
But I did manage to make the sniper scroll wheel change colour! I'm keeping the map for later, because it seems much easier to do once I have all the resources necessary for it.