Indy, I'm like you; I have a few more timeless type pieces that are dressy and I do have occasion to wear them a few times a year. Not so much weddings, but going out for a more special dinner, birthdays, charity events, etc. That's why I bought the dress I did for my son's wedding. Every few years I take stock and clean out this part of my wardrobe.
I used to think that I couldn't wear black at all. I am more of a "fall" color type person (jewel tones), but I wear almost all black, grey, or off white/white now, with a splash of red or pink. I find that using accessories with color and the right make up takes the "tired look" away. I know you've said you don't wear make up, Shooting Star, but for a special occasion, some neutral type blush and a little lipstick might make a difference.
The blouse is lovely. Maybe a colorful wrap/sweater, if it gets chilly?