All this debate can't resolve the fact that enforcement of what is written is spotty, arbitrary, and, at least at the street level, subject to much interpretation by the patrol officer.
F'instance, I started wondering when Indiana repealed their "Ape Hanger" law for motorcycles, given the number of shoulder-high and higher handlebars i see everywhere.
Well, the LAW still says "no more than 15 inches about the saddle" so what's the deal here? 40 years ago, Bikers were "scum", and The MAN got his rocks off jacking them up.
These days, you hassle a group of bikers over their handlebars and various other offenses, like noise laws, and you'll probably get your ass chewed by your Chief for hassling the CEO of the local investment bank and his friends, who complained to THEIR friend, the district's member of the US Congress...
I guess the point of this epistle is to say that people want to know "Can I get away with this?" and the best answer anybody can give is "Maybe, maybe not, but the Law is the Law, and the cops are perfectly within their rights to either ignore you or enforce it To The Letter, as they see fit."
Just yesterday, I saw 5 of those "no spare parts available" Chinese scooters on the streets of Lafayette, none of them with plates, all of them being driven at 35-40 MPH. Legal? Oh, goodness gracious, no, but there they were, just the same.
I guess what it comes to is that only YOU can decide just what kind of consequences you're willing to suffer if you get pitched by a hard-ass who's looking to impound a set of wheels. Run 49CC and less than 25 MPH and laugh after he lets you go, or ride a 40MPH "66" and don't come crying to us if it gets towed.