Select an MDF Lazy Susan from a local craft or home store. Choose a midsized version--large enough to hold all of your ink pads but small enough you can fit it in your work space. Sand and shape a piece of vertical wood that will serve as the "backbone" of your carousel.
Fuse the piece of vertical wood to the Lazy Susan with the wood glue so that the end of the wood is held onto the very center of the Lazy Susan. Apply firm pressure for one minute or as your wood glue's instructions require.
Attach the eight old cassette racks to the wood piece, using Gorilla or Krazy Glue. If the cassette racks are sturdy enough, you may opt to use small nails instead. Spin the cassette racks to ensure they are fastened together well and can hold the added weight of the ink pads.
Carve an oval hole into the top of the wood piece to create a carrying handle. Use your wood scraps to shape two rounded pieces of wood. Attach these to the perimeter of the cassette racks, so there is still adequate space between the wood pieces and the vertical wood backbone. This will serve as a storage shelf for oddly shaped pads, punchers, or anything else you'd like to stow away with your pads.
Paint your carousel any color you'd like, using either a wood-friendly paint or a standard craft-based acrylic. Allow the paint to dry. Add a second coat if necessary.