This post highlights some of the differences between the wing root fairings on the Model 110 versus the Model 90A. Here is a picture of NC18629, a Model 110, in the museum at Oakland airport:
This picture also highlights the additional challenge presented with the Model 110 at the front spar attach point wraping on around to the windshield. The shape of the Model 110 is different than the Model 90A. Also note the wing root fairing is done in several segments, riveted together. On NC18629, the gas tank outlet is uncovered.
Above is a cropped section of the high resolution photo I have of NC12350 at the Monocoupe factory. The wing root fairing is again in multiple segments, but the gas tank outlet is covered.
Here are the fairings that came with NC12350 and I believe them to be the originals.
The part that covers the gas tank outlet is pretty wide to accommodate the bend between the outlet and the gas line.
Here is how I did mine:
I put a small angle in the part that covers the tank outlet and also streamlined it down towards the back.
Here is how these look on a Model 90A:
Here is how DJ did his: