Thanks for your help!
Sorry for a slow reply - I got busy with something else. I'd really like to pursue this though, as the firewire in is still useful for old-school SD video.
In QuickTime X, the camera input appears as the name of the camera - (Panasonic) NV-GS55. Screenshot attached. That's what appears in Resolume 5 also. In 6 I get nothing other than the FaceTime camera.
Any (more) help v gratefully received!