The 67 uses a single transverse strap and the 71 would have 2 straps running front to rear. I do not think the tank is dimpled correctly for the 67 strap. Venting may be an issue as well. The 67 tank is a one year only tank.
When I looked at it I didnt see any extra vent ports. He wasnt sure what year it was but the fill tube only looked to be about a foot long? This is just for a daily I am building so I hope a can make it work.
You might be able to make it work. just bent the flanges in on the sides. The fill tube might be pushed into the tank. On the early years 67-72 you can take the tank out with the fill tube in it. Later models it must be removed because they are installed on the outside of the quarter.
Plug all vents on the tank and use your fill tube it has a vent on the tube. its all you need.