Hi Adepose,
My mum is in the same point in her discovery/MM journey. Just diagnosed. I met with her doctor and her last week and they're starting her on the MPT... Melpholan/Prednisone/Thalidomide cocktail. (if not Thal. then Revlimid... depends which group she is randomly assigned to...). It's an oral chemotherapy blend with the pred/steroid component which by itself would do some good but in combination does the most good to bring the myeloma under control.
After 75 they are not candidates for Stem Cell Transplant, but if they can tolerate the chemo and withstand the side-effects of the steroid, they can hope for a manageable yet chronic condition. (These are the side effects we're going to be watching out for: neuropathy, blood sugar issues, loss of muscle mass.)
We know people in their 70's and 80's who have had it for 10-15 years. If your father, like my mother, was very tired and anemic but not yet experiencing bone pain, they may be lucky that it was caught early enough. We're hoping Mum will be around for a while!
Hope that helps a little, but it's all individual of course.
Best to your family,
Sarah