Need help with this caliper (pix inside)

This caliper is supposed to be for a '78 KZ400. Can anyone confirm this? Also, how can I remove the mounting bracket? I removed the C clip on the end, but it will not budge. I will not turn (assuming it is threaded) and I can not move it by trying to pound it out.

Please take a look at the pix and tell me what you know!