3d Modelling (models already created but need to be put on sprues for casting)

Design details: We have already had created approx 48 charm designs for our jewellery business. Our current 3d modeller has let us down and we are in need for someone to create STL files of our charms, 4 charms per file connected by a sprue (All this has already been made once in one file which i can supply) The current file contains a mixture of desgins, what we need, is that file broken down into each individual design and sprued.
Ideas for the visual style: Style has already been created as per attached file
Extra notes: I have attached an example STL file so you can get an idea. The end result we are looking for is an STL file for each design made up of 4 duplicated charms joined together on a straight sprue. (Totall model must not exceed 54mm in length)