Morel tweeters in my experience have had serious QC issues. I've even had a brand new pair of Supremo 110's that came with motor assemblies way out of alignment and rubbing like crazy. Fortunately their customer support is good.
If you have a Morel that's known good, I'd say best bet is to replace the diaphragm instead of risking it with a new driver. Do you know the tweeter you have uses ferrofluid? It might not ... and even if so it's not something I'd worry about.