Magnequest Mike made a lot of different transformers - which ones do you have? There are a few that could work, with suitable modifications (minor circuit changes and a few new mounting holes.) It won't save money (custom packing is costly) and Bottlehead strongly recommends building the kit debugging it in stock form before making changes; otherwise we are not able to provide as much useful help when things go wrong. But it can be quite satisfying to make use of something you've laid away long ago!