Merc 7.5 venturi?

I have a 1985 Mercury 7.5 with a broke venturi-one of the wings is missing. My carb is the wmb-4 and there is a tillotson carb that can also be on this outboard according to the parts list. I can find the one for the tillotson carb but not for the wmb-4 carb. Part number for the tillotsun is 69764 and I can not even find a part number for the wmb-4. They look the same on the parts diagram so my question is would they interchange? Is it even that important? I would think they put it in there for a reason but the motor seems to run good now (in a barrel LOL) Any body able to help me out? Also posted this on another forum but thinking Pappy might know! Thanks , Jim

After checking a place online it doesn't look like it would work. My carb isn't listed on the ones it fits. So does any one know the part number for a wmb-4 7.5 carb venture? The online parts places I tried didnt list a part number separate for it?