Junimo Magnet Model, made to fit magnets that are 10.4 x 9.1 x 2.8 cm
The ones I used when making these can be found here.
An the glue I used to adhere everything together is Gel Gorilla Glue, which can be found easily at your local home depot, rona, or hardware store.

You can print the Junimo as one solid entity, or separate parts to have each piece come out as a specified colour. Then use some super glue to adhere all the pieces together.

It is recommended to stop the print to place the magnet inside so the layer prints over top and binds the magnet to the Junimo.