Back when FLAPS hired professional parts guys instead of nose-picking computer jockeys, finding that kind of part would be a no-brainer. Dorman and Edelman brass fitting assortments were well-stocked, and the counter guys knew how to research their catalogs and come up with a correct part number. That item is a "pipe thread to female inverted flare adapter", and NAPA would probably be the most likely place to start looking. All you really need to know is the size of the pipe thread (usually 1/8" NPT or 1/4" NPT) and the diameter of the metal tubing that threads into it.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!