OK, I just picked up a Bargain-grade Hasselblad 500C/M outfit from KEH.com (JOY!) But I have two concerns: 1) When I look through the waistlevel viewfinder, there are numerous black dots everywhere, and a wispy, hair-like scuff in the upper corner. Is there any way to get rid of these with a clean, or is this irreparable damage? 2) After I shot frame 12 of my first test roll, I think neither the main winding crank nor the one on the film back would wind. Confused, I popped out the film holder and found out I wiped out frame 12 and part of frame 11. Did I do something wrong? I have since put color film in there and shot a few exposures just fine (though not to 12 again yet) Thanks for any suggestions. I'm asking you guys since I'm operating this camera on pure intuition, and these might be common problems that Hasselblad owners know about.