I need to scale one end of a model

I have created a fairly complex model and now realise that I have made an error in one aspect of the dimensions. Rather than redo the entire model I can imagine a fix but I’m not sure if this is even possible.

My imagined solution relies on fixing the complex model in some kind of 3D rectangular bounding box and then scaling one face of the box in the Z dimension such that the bounding box becomes more of a trapezoidal shape.

My hopes increased when I read about the scale cage tool but this scales all faces by the same amount

If you can imagine my model fitting inside the ‘before’ box and then the model being scaled in the proportions such that after scaling it would fit into the ‘after’ box then you have managed to visualise what I’m trying to achieve.

I hope there is a fix for this and I look forward to hearing from anyone that can help.

Russell