I'm looking for a gasline elbow that is a flare fitting on one end and threaded (27/in) on the other. The gas nipple (or diffuser - different ones for natural gas or propane) screws on to the threaded end, and the flare end leads to a copper line that goes back to the burner valve/control. The elbow is brass. Where would I find what looks to me to be a pretty standard piece of gas hardware? Thanks, Joe