Here is what I came up with:
A. Two 3 inch screws for each can
B. Plastic tubing cut to 2 1/4” lengths (This allows 3/4" of the screw to go into the wall)
C. Slide screw into tubing
D. Position 2 tubing encased screws on wall 2 7/8 inches apart. This provides tension on the indentation just below the metal rim of the Tennis ball can.
BTW : The label comes off the tennis can easily
Fill it up, push it into place, just pull it off the wall to take it to your project. The can's cap make for a nice no spill container.
I used a Sharpie to mark specific sizes