i would frame this whole post as a good example of people thinking the worst, and it turning out to be something so simple. glad to see you got your problem fixed in the end man, i would say that you'd know if your flywheel was a dud. it wouldn't make any noise, it would either be on working as it should or if something was loose ... the mass of it, it would rip itself off the crankshaft and you would loose all drive
It's not just on 133's. I have this as well on a certain acceleration I get this 'slightly vibrating noise' and it seems to come from the glove compartment.