I had my TT mid-May 2006 for Graves and donated my first pint after surgery on July 1st 2006. I had a pretty easy surgery and a fairly quick recovery. I specifically asked both my endocrinologist about giving blood (he didn't have a problem with it from my safety perspective) and told the Red Cross I had an autoimmune disease and antibodies (evidently they didn't have a problem with it, and Graves isn't on their list of diseases that cause deferral). I have been regularly donating every 8 weeks since then with no problems.
I'm a donor, and am really bummed that I can't give until I'm 5 years cancer free!! I couldn't remember if you had thyca or not, though. If not, I'd call the Red Cross and ask. Please let us know what/if you find anything out.