How do you distinguish Carter YS models?

Hello again,

I've got a spare carb in my "box 'o parts" for my 1953 M38A1. It is stamped YS on one side and has 0-818 casted above the patent numbers. I purchased a YS rebuild kit from Midwest Military and want to make sure this is the correct carb for my Jeep (F-134) I understand there are different YS variants so I want to make sure this is the right one for me. Is there an easy way to tell which is which?
Rob

 

maybe one of the guys who really know will chime in
my book says model # 950S , but it's not a Jeep book I trust
my flattie originally had that type on it
I swapped it out for the civi model; why, I don't recall
if they are like the YFs, seems it should be stamped somewhere in the body
not cast