Take the old tube to a Good Water heater type or oven type repair place. Odds are they can cut and "Fit" a tube for you in a matter of minutes.
Kind of like the custom Muffler places that cut, shape and bend pipe to need. In fact exactly like but smaller pipe.
Home was where I park it. but alas the.
2005 Damon Intruder 377 Alas declared a total loss
after a semi "nicked" it. Still have the radios
Kenwood TS-2000, ICOM ID-5100, ID-51A+2, ID-880 REF030C most times