I had a 70-71 for sale and its sold.
I have my old 72 filler tube, but the mouth of it would need worked to make the correct cap fit it right......thats why I swapped mine out to begin with.....The cap I was using on it didnt fit right....and the correct cap didnt click in...but it might be abel to be tweaked to work if you have the right cap to keep testing with....
I also have another 70-71 tube but it has a small pinhole that would need repaired. The 70-71 version has the depressed "bump" in it.
If interested, PM me.