[Kube]

The very first routing of an authorized filter returned the oil to a special fitting that replaced the left bolt; fuel pump to stand.
The second routing went to the timing cover via a special bolt.
This routing was changed as it seemed mechanics were installing that special bolt at the fuel pump stand not where I'd previously noted but rather, they would replace the left bolt that held the stand to the valve chamber cover.
This easier to install "modification" worked but resulted in a higher consumption of oil.
Thus, the second design to the timing gear cover.
The third design, 1941, routed the oil back to a boss near the front (left side) of the oil pan. And finally, 1942, a special fitting was riveted to the pan held both the dipstick and a boss for the return line. Simply eliminating a separate fitting on the pan.

The bottom line in my opinion? Where you are thinking of installing the return line would not be a very good choice.
Ford rarely (ever?) changed things for no reason.