Old cars just had a vented gas cap... nothing more than that. In your case, you could grab a small filter for a PCV system or whatever and run your hose to that. Make it as high as possible of course, should you need to ford water. Of course, when you say safely and properly, that's through a charcoal can and hooked to your intake via vacuum valve.
I have a can on my YJ tub I planned on using, but I can't tell if its working or not; I still have a gas smell in my garage. I've seen the links for the delorean (?) canister, but does anyone have the make/ model/ years of vehicles that have these? A suggestion that'll make it easier to find the right car in a JY?