I'm putting together an AC system in my '42 Dodge Carryall and was looking into what would be needed for some nice Hard lines. Looks like you can convert somewhat to a 45 degree flare system.
I have ordered some parts from these guys and its been good stuff for the price and ships at lightening fast speed. 45 degree flare looks easily done with the Mastercool unit posted earlier in the thread. 45 degree is the angle of a brake line bubble flare too right? So you could probably use a 3/8" brake flare tool to run your -6 size hard hoses.