Dan,
I lost my husband in April to Hep C/cirrhosis. I have it also. The link Berta gave you to hcvets.com is the best info out there for vets with hep c. My husband's claim was successful in large part due to the info from there, and how it was presented. He was granted service connection for the hepc due to airgun injections, and we used the claim info Berta was talking about that the VVA won. If you go to that website, somewhere on there is a link to the message board, and Harry, the forum manager, has a file he can email you with a lot of medical evidence in it that can help with your claim. I believe the nexus letter that my husband's dr. wrote for us is in the file also, and there is another nexus letter on the site. If you are still going to get one, make sure it states that it is "at least as likely as not" or "more likely than not" that you contracted the hep while serving and that the dr. addresses all risk factors you were exposed to. The syringes that were used were used with multi dose vials, which were pulled due to the risk of bloodborne pathogens, the info on that is also in the file Harry has.
If you (or anyone else) have any questions or problems getting the file from Harry, please feel free to email me at dock671@gmail.com.
Good luck
Lori