This has disaster written all over it…
Rubber hose??? Please don’t, or at least tell us which roads you drive on so we can avoid them.
Teflon tape on the threads doesn’t do anything. The flare is what seals the line, not the threads.
Unless its a double flair it’s illegal and unsafe.
If the line was rusted which is why it broke in the first place, you’ll never be able to cut it out and flare a new section well since odds are that’s rusted too and never seal well.
Brake line is dirt cheap. Just start at the closest junction box and work your way back with new line.