Take the fuse to CT and match it up, even with something higher such as 20A (they don't sell 15A).
You need that spring. Put the mechbox 95% together with the trigger spring relaxed, then use a small slotted screwdriver to push the tail in place when you have the mechbox halves together with a couple millimeter gap around the trigger. V2 is easy compared to V3!!!! Lol
Definitely !! I gotta hate those V3 triggers hehe !!