OK, through the power of deductive reasoning, I figured if I had all of these collets, there had to be a way to use them, especially after finding the taper with a collet in it. So, I measured the dia. of the tail of the collet and found it to be .50. I then turned a piece of the 5/8" aluminum bar I found to .49 for about 3" in length.

I then stuck it into the tail of the collet and found there is a stop ring for it to rest on. I did a little measuring and cut the bar off so the larger diameter would go up into the opening on the taper

I then measured the hole in the back of the taper and found it to be .52 I turned the aluminum bar to .515 and assembled everything.

Everything fit tight and locked up as expected. Chucked it in the lathe and spun it up. It runs true. Eeehaaa
Now all I have to do is get a steel bar and turn to the same dimensions and I will have saved a chunk of money.