^Take it easy man, I was only kidding with you.
Anyways, I found the measurements for both Zatiny 8B4 and Zatiny 8E7 from a Korean site.
Just click on the picture on the left with the chart on it and it'll give you the measurements. Although I can't read Korean, I can tell that the first measurement is the waist and the second one is the waist without the dip.
Zatiny 8B4ÀÚÆ¼´Ï 8B4 (À¯·´ÆÇ) µðÁ© DIESEL ZATINY Diesel
Zatiny 8E7ÀÚÆ¼´Ï 8E7 (À¯·´ÆÇ) µðÁ© DIESEL ZATINY Diesel
From what I've seen so far, Zatiny 8B4 in W31, has a waist of 41.5 cm while Zatiny 8E7 in the same size has a waist of 42 cm.
So I'd probably size down on these and let it stretch out to perfection.