TOPIC: Merc 4 HP carb

Hello, I'm new here and looking for advice.

I'm working on a Merc 4 hp, not sure of the year. It's in great shape with little time, but the carb is awful. Butterfly valve is locked up, and I just can't seem to free it no matter how much I soak it or spray it.

I'd like to find a rebuilt carb, but haven't had much luck. Serial #'s posted below, if anyone can help please let me know. My phone # is three eight six 308-3742. Thanks.

Merc serial # 3163298
Carb says; Mercarb 1399-1133
Carb has another stamp # 010739