i'm assuming you had a california version. they are the only firstgens i know of with a vent line. i have never seen one. i assume the vent goes from the tank to a canister.
if you are not living in california currently, i would guess you could set it up like mine ('68 bird).
fuel line from sending unit to fuel pump only. no vent.
take the vent line and store it or stow it. plug the canister or remove it.
if you live in california, and are going to be checked for the vent line, you can either try to find the right tank, or leave the line in place and plug the end of it and hope no one calls you on it.
dont know if this helps or not, but i hope it does. i didnt know how to respond to your last post. dont know if 2nd gen units fit the tank or not.