Mac, The round slide Teikei carburetors have a single fuel inlet between 2&3 carburetors just above the bowls and inline with the fuel pipes that join 1&2 and 3&4 carbs.
If my memory serves, there are three brass fittings on the sides of the carbs. Two of these barbs are for venting the float bowls and one is for engine vacuum. If my memory is correct, the vents are on 2 & 4. I think the vacuum is on #3. You can tell by looking at the one for the vacuum as it is just a hole going directly to the inside of the venturi. The hole will be located on the inside of the carb adjacent to the vacuum barb just behind the jet needle/needle jet. The vents connect to holes in the top of the bowl cavity. I think the little Teikei carbs have aluminum tees inserted between 1&2 and 3&4 to connect the vents for these pairs of carbs but again this is just from memory.
If you still have a problem, let me know and I will look at a set of those things and get back to you...