[Greg Reid]

Check your local parts store. I bought a Spectra tank for my 68 right over the counter. They had to order it from the warehouse but it was there by 1:00 p.m. and no shipping. The price was a little better than I had found online also. The disclaimer is that it was probably 10 years ago.
By the way, mine still looks brand new after having been on the car for a decade at least. I degreased it with lacquer thinner and sprayed it with clear.
On the sending units, I think you should keep your original if it still works. I've heard stories about some of the new ones crapping out after 5 or 6 years. Frankly, mine can be a little flaky from time to time... I replaced it with the tank.