He'd get married with his real name, same as when Norman Maine and Vicki Lester get married with their real names in "A Star Is Born". It probably would be a good idea for him to get out of town after a while, since Charlie Cowell is going to be coming back at some time and stir up trouble. But hey, happy ever after and what really happens afterward can be applied to any musical. You think incredibly manipulative Laurey and Curley are going to be happily married in "Oklahoma!"? Not bloody likely, as the original Eliza in "Pygmalion" would say. Or Eliza and Higgins? Lots of turbulence in that relationship if they go on with it. "The Music Man" leaves its audience and the people in River City feeling good at its conclusion, and sometimes that happy satisfaction is more than good enough.