None of your choices here are particularly good, so it's the matter of picking between two or three evils. A similar English approach would be to say Aunt (Auntie) and Uncle, but that strongly implies blood relationship - though not necessarily so. Old Man Mykola would sound perfectly fine, but Old Women Orysya doesn't, so this is probably no the way to go. Hence the suggestion above which should be at least acceptable. Good luck.