Carburetor Question - Is this a good call?
So the carb looks like an updated 1850 although from the little bit of data on line, I can't see what the difference would be between your carb and an 1850. Both are essentially emissions carbs so the tune up should be very close for what you are doing, once you get that wacky adapter off there.
Now, on to the plugs to see what they are.