Moped Army

Hi i have a 78 bravo but im not sure what kind. I have a plastic gas tank and bought a metal one but it fit differently on the bike. Also i bought an engine for it and it was different. The original had two piston rings and a longer piston than the one i bought that had one piston ring and the piston was a bit shorter. Im not sure if it is a deluxe or super deluxe or just a regular bravo. Did the deluxe/super deluxe have a whole different piston? Thanks