Peppy, your Gypsy looks a lot like my now deceased girl, Penny.
Penny was almost 7 y/o when I lost her.
Gillian, they do have a musky scent, since they're part of the weasel family. I used to call Penny my stinky weasel.
You can easily potty train them, and they're smart as whips. However, they're balls of furious energy, and the best description I ever heard was that they're like kittens on crack.
They're either going full bore, or they're asleep. I've seen them fall asleep in midstride, and then it's like they're in a coma.
Interesting, funny, amazing little critters. I'd love to get another one or two eventually.