Honestly, if the damage is not severe, leave it as is. In order to re-coat the lens, the old coating first has to be polished off. I don't pretend to have enough experience or expertise about this to offer any opinions with authority, but I have certainly read that this process can potentially affect the profile of the front lens element which, of course, means it might impact on sharpness across the frame. I am sure there must be firms such as the well-regarded Focal Point who can perform this with satisfactory results that do not compromise optical performance, however there is always a small risk the glass will fracture in the process. I have previously discussed this exact point with my local optical manufacturer and repairer on whose advice my remarks are based.
I have a 2.8D here that will most likely need this treatment when I get around to it, but it has quite bad coating deterioration, including what looks like a fingerprint etched into the coating (I assume the result of etching by skin acids over an extended period, as I can't imagine how else this could have occurred). The lens is a Xenotar, of course.
Is the lens of your 2.8C a Xenotar or Planar? I'm guessing Xenotar, these are infamous for coating defects as they have aged. Both lenses were available in the 2.8C though. The Xenotar has a front cell that is a single piece of glass. As I have researched myself, I understand that the 2.8 Planars are a bonded front pair making polishing and re-coating more complex.
The bottom line is if the marks are minor as you say there is little to gain and much, potentially, to lose by attempting repair. Image quality will not be improved, whether vanity alone is worth the expense and risk is for you to decide, ultimately...
Regards,
Brett