[Ron Ramirez]

So I tried again just a few minutes ago.

I could not get the bakelite piece out of the first can without breaking it.

Then I ground the lip from the end of a second Sprague cap.

After doing so, I made a discovery that you guys who have done this before had not mentioned.

There is a rubber ring at the bottom of the bakelite piece. This is what keeps the bakelite in and may prevent its removal.

I found that if I carefully went around the bottom with a knife, cutting away the rubber ring between bakelite and metal, that the bakelite piece could then be removed fairly easily.

I had ground enough material away from the first can. It was the old, hardened rubber holding the bakelite in place.

Results of the first (left) and second (right) cans, below:

   

Now, if I could only get good enough with my Ryobi "Dremel" tool that I don't let it slip and mar the outer edge of the bottom of the cans...