Here is a great looking long sleeve dress by Oscar de La Renta boutique. Amazing fabric in brown and oatmeal. Skirt section almost has a quilted feel to it. Zippered back, a snap at each cuff, and built in tie at collar. I can't find anything online even remotely similar to this one. While I wouldn't go so far as to say "one of a kind", but I'd definitely say good luck finding another one like it! An amazing designer piece in excellent condition with tons of life left. Here are the exact measurements. (be sure to reference the last photo to see how I measure dresses)

Here are the measurements:

Bust 18"
Waist 14 1/2"
Hips 23"
Length 44"
Sleeve 25"

This item is sold from a vintage boutique in Roanoke, VA.