Need to hunt for some originals marked AUTOLITE. The challenge is that heater hoses, like radiator hoses were replaced often just out of concern not failure after a number of decades or even less
Have found, out on the web some builders/owners who have figured out their own way to reproduce their own stripped hoses. Borrowing (thanks to all that posted) pictures from their efforts I share with you just a couple to hopefully provide some possibilities and ideas to others here on this site.
Fixture #1 - Looks like maybe vacuum hose but you get the idea or some ideas
There is another method, though similar that I will find and post here also