Fill pipe 3/4 MHT x 3/4 MHT or 1/2 FHP Hose Adapter
. I wanted the finer thread on one side to thread into pvc.
Outlet1/4 x 1/4 brass adapter
. As long as the barb side is 1/4" the thread can be what ever you want, I found the smallest thread possible.
Cap 3/4 Inch Garden Hose Cap
. Generic cap you will need an extra garden hose gasket to act as a retainer for the plastic/sheet metal vent piece.
Diameter will be determined by desire application and/or required volume just make sure you buy 2 pvc Caps of the same size, I found that anything over 4" diameter gets crazy expensive.
I will hopefully have the tank cleaned and mounted for pics before the week is out.