I have a furniture (vertical) dolly I picked up somewhere that is curved, on the back part, not flat. I do not even have to strap them on it, just learn it far enough, hold the cap and they stay. Takes a lot of weight off me. I can roll the large ones, but hate to run over things with heavy steel. Only one small tank left, but they do not roll well to move them.

The handle idea, might want two on there or a long handle, then attempt to get in the center.