Unless you're hung up on a bone-stock buildup, why not step up 1/16" and plumb the line with 1/2" tubing? The end fittings are 1/4" pipe thread, right? It won't hurt to use readily-available pipe-to-flare fittings and adapt the line to 1/2" tubing instead of something that's so hard to find. If you need to drill the flare fittings out for a slightly larger internal diameter, there's plenty of material available to do that without weakening anything.
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!