Hasselblad Super Wide C filter retaining ring

Hello all, I got an unbelievable deal on a Super Wide C and am trying to furnish it with basic accessories. I know virtually nothing about Hasselblads or any cameras for film larger than 35mm, so please bear with me. First thing, I would like a haze/UV filter to protect the front of the lens, and it needs to be a series VIII, or 63 in Hasselblad terminology. I'm aware that I'll need a Hasselblad-made filter so that the two glass surfaces will not touch. I'm looking at the lens and it seems to me that there is a filter retaining ring on it already. I'm attaching a picture of my camera and one of a ring I found on keh.com. However, the ring on my lens does not budge when I try to loosen it by hand. Is it a good idea to use a filter clamp to turn it? I'll be asking Mr. Odess to overhaul the whole thing, so no big deal, but my curiosity is getting the better of me :).