Here is a simple save editor that I made. There is one weird aspect to save editing that I haven't been able to figure out.
When I load in a modified save, if I go into the Upgrade area and select a ship, if it's not normally available the game will revert it to what is available. However, if I load the save, and immediately start a game then everything loads correctly, including the Upgrade area after completing a level. I think it has something to do with editorLevel, or how I make everything "available" but I'm not entirely sure. Any advice would be appreciated.