B&m line lock help

Im trying to install a b&m line lock on my 67 barracuda. Im installing it to lock the rear brakes out so i can still control front brakes while doing my burnout. My issue is im having a heck of a time trying to find the adapters to thread into the 1/8 npt threads on the line lock and also thread into standard 3\16 brake line. Which has 1/8 inverted flare fittings. I know i could use compression fittings but really dont want to cut the brake line at all.