I can imagine how frustrating this is for you to get a proper diagnosis.
One thought came to my mind after reading some of your other posts. Do you have psoriasis? I don't see it in your signature, but I did see you mention it in a reply to winni on the UC board.
Has your rheumatologist considered Psoriatic Arthritis, which is also in the family of spondyloarthropathies, even though you've tested negative for the HLA-B27 antigen. You mentioned your rheumy doesn't think you have RA because only your right hand has swelling, not your left. The asymmetry is common in PsA (psoriatic arthritis.)
"Asymmetric arthritis makes up about 70% of all cases of psoriatic arthritis. It often involves one or a few joints, like the knee, hip, or fingers. Although it's frequently mild, it can sometimes be debilitating. The inflamed joints may be red and hands and feet may be swollen."
These are also a couple of good links:
I was originally diagnosed with "sero-negative inflammatory arthritis" in 1991, since I was negative for the rheumatoid factor. Between 1997 and 2004, I had iritis six times, so I convinced my rheumy in 2004 to test me for the HLA-B27 antigen. I'm positive for that, so my rheumy now calls it spondyloarthropathy, and I'm on Enbrel, which works fairly well for me (not as well as my first year with it.) Enbrel is also prescribed for PsA, so that might be one of your options. I was also diagnosed with IBD in 2003, but that diagnosis is currently debatable. Oh, like you, I also have Raynaud's, fingers and toes, and man, I hate winter!
Anyway, good luck. I hope you get the right diagnosis and some better medication.