Thanks again, all.

While I appreciate the opinion that Gibellini should replace the frame for free – I'd be lying if I didn't secretly hope that would be the case, who wouldn't to save money? – I'm realistic about the fact that the camera is out of warranty; that I'm not the original owner and have no idea what the camera has been through. It looks otherwise almost mint, but it does look like it has seen some wet plate work. I plan to send them the camera to them tomorrow, and who knows. Maybe they will take pity on me.