We have had a few 'meetings' with Saffy on a leash.  She starts out pretty chill but then gets excited as "C" moves around more and more.  At that point I end the interaction.  Saffy did get to sniff her rear and "C" sniffed at Saffy's side.  No lunging on Saffy's part, which bolsters my hope, but I am still too nervous.

Saffy managed to make a mess with a ("treat"-free) litter box that I got to vacuum up.  Here's hoping that intrigue dissipates.  "C" goes to the vet later today for the little bump at the corner of his mouth.  He is starting to get bolder about trying to get into things and jumping up on items I would prefer he wouldn't.  I know he's a cat, but I am going to try and keep some things out of bounds.  I'm hoping early and consistent persistence pays off.