Okay, these "fuelers" that are mounted in the cowl somewhere are fine but you need to by a set of "Hemostats". You see the fuel line will come out through the firewall as normal and go straight to the carb right? Well somewhere between the firewall and the carb, you cut the line and put in a "tee" fitting. Thus the line continues on to the carb and your new line is the one you connect to your fueler.

The big trick is when you fuel this way, fuel "WILL" run out the carb. You use the hemostats to pinch off the line by the carb to prevent the fuel from running out while you fuel. When your done fueling remove the stats.