I bought the OP and beret secondhand and wore them once, and I'm including the matching pumpkin macaron brooch which I bought new. Some of the bodice lining seams are pulling apart and have been mended, which I tried to show in the last photos, but the external fabric seams look fine. It is not the same as the OP currently on the Lady Sloth site, but it does seem to be the same XXL. The fabric does have some stretch, so I could wear it with bust 113cm and waist around 100cm.

Approximate size:

XXL: Bust 108 cm, Underbust 98 cm, Waist 94 cm, Back width 41 cm, Bodice length 42 cm (normal waist), Skirt length 58cm (normal waist), Sleeve 64 cm, Arm 36 cm, Bottom 280 cm