VINTAGE GLORIA VANDERBILT BLOUSE--SIZE (B4)

Vintage Condition and minimum odors/no rips See photos for condition and a few vintage stains on this piece Large collar-and I am not sure what size is B4 and I tried to look the size chart online and could not find comparison size. Long Sleeve--100% polyester Light weight and many buttons and 2 button on sleeve 30"L x 25" W sleeves+23" I would say this would fit XL-2x