The German "Sturmgeweher 44" in WWII was the first actual "assault rifle". It's name actually translates as "assault rifle" and it was he first to have a select fire switch, which is the defining feature of an assault rifle. With the flick of a switch it can go from semi-auto fire to full-auto fire. Normally it fires a mid-size round powerful enough to be used out beyond 300 yards but could still be controlled in full-auto at close range like the submachine guns which used the smaller pistol-sized ammo such as the 9mm or 45acp.
Enjoyed the joke of your longrifle with all those cosmetic changes, but without a select-fire switch, I'm sorry to say it doesn't meet the bare minimum for the definition of an assault rifle.
***moderators***, I will not be offended if you delete this. Pretty strange talking about assault rifles in a traditional muzzleloader forum, even if it's mostly in jest. But the use of the term being so loosely used to label something that is not an assault rifle as one is a personal pet peeve of mine.