This may sound old, but maybe it will save a lot of grief and four letter words to some. I use NH carburetors on all of my cars, even though it is not year correct. This procedure was done on a 1913 with the correct aluminum manifold, and would be the same for any Model T with the manifold on the car. First, I put the two bolts into the manifold with the gasket, with just enough to hold on the gasket. Second, I feed the gas line and the priming wire into the proper places. You are supporting the carburetor the entire time with your hand. Make sure the carburetor feed pipe nut is up where you can get it started while everything is loose. Third, swing the carburetor up to the manifold with the feed pipe and priming wire engaged and push the two bolts through the carburetor flange making sure you don't lose the gasket.
Fourth, getting a wrench on the nut side of the carburetor can be difficult, so after starting the nuts onto the bolts, simply insert a screw driver between the nuts and the carburetor, and that will keep them from turning while tightening the bolts. I use a thin wall deep socket on the manifold side which enters the head of the bolt about 3/4 of the way, enough to hold it.
Since everything is in place now, tighten the feed pipe nut, and attach the throttle rod, and the carburetor adjusting rod, and cotter pin everything.