By popular demand, work continues on the Undo function, which I started, got it wrong and had to Redo.
The method I am using will be much better than the BTB one which really just saved/loaded the entire Venue each time. The new method only makes changes to piece that was changed. Of course if this was terrain then it can affect everything that cuts into or rests upon it, but if you’ve just moved an object, then it an Undo will work much faster.
Thankfully I did have a little foresight (who would have guessed that people would want an Undo function??) and designed the code in such a way that facilitated this. There is still much work to be done as every single function or type of change that you can perform needs to be catered for. I also need to overcome the menu system, which for some reason wants to act unusually in this framework.