When you say the primary gear did not move against the springs ...
Me experience is that you will never be able to move that primary gear against the springs once the clutch has come off the bike. I remember the first time I took a clutch off and examined the primary gear and hub. It was obvious that the springs were some kind of cushioning mechanism and that the primary gear and hub would therefore be able to be rotated independently. But it was impossible to verify this with just your hands twisting them in opposite directions.
I'm guessing you need to pass 80 odd HP through it to be able to feel any movement. So basically, I'm pointing out that you assumption that they are seized may be flawed. They will just appear seized.
The problems with these hubs are that the bigger of the springs (there are bigger ones and smaller ones) get compressed over time and start to rattle about in their sockets. There are various fixes for this, including leaving them alone, putting washers at either end of the springs to compress them and as said above, grinding off the rivets on the backplate, replacing the springs and welding it back up again (sometimes replacing the thin backplate with a thicker one that doesn't warp).
It all depends on your application. For racing, you should replace the springs and the backplate. Clutch explosions and severe engine damage will result at some stage if you don't. However, for most of us, we either find a replacement hub, that is not so badly affected or we put it back in and hope for the best.
Something about the noise you speak about: you can see the springs are loose and that they might rattle around somewhat. But is that the noise you can hear? Mostly I would say that it isn't. The clutch noise most of us hear is a rumble and not the rattle of loose springs (which I figure would by centrifugal force be tightly held to the outside of the hub). This rumble is the whole clutch itself. Yes it can be a loose clutch hub nut but even when it's tightened up fully, there is often a clutch rattle.
See some of my vids on the problem:
https://www.youtube.com/watch?v=Yj6vAyaUqN4&list=PLAehDwjsoR1snALu0BfyONivII01jQDMT
My opinion is that its usually to do with lateral movement of the clutch hub on the shaft. This is often caused by the fact that the clutch hub spacer is not exactly the same width as the clutch hub. In later GS1150s they came up with a series of shims to alleviate this problem.
I also found (contrary to popular opinion) that the tiny rubber grommet placed in the little hole on the primary gear side of the hub and the oil pump gear spacer stops quite a bit of flapping about noise.
Your problem with the wear on the springs themselves does indicate the severity of their looseness. It looks to me like you need a backplate rebuild or a replacement. Just don't expect that to eliminate that GS clutch rumble you may be hearing.
