I'm trying to unwrap a few faces of my model at 1:1 scale to fit onto an image that I've prepared to be 1:1 scale as well.  Everything I've tried has resulted in a distorted unwrap one way or another. The closest result I've found is to unwrap with Cube Projection - that seems to keep the relative locations of the face correct, but the X and Y scale needs to be manually tweaked.
The desired result will have the X and Y scale at 100% of the original (or at least X and Y will be the same), and the relative positions of the faces need to be the same as the original.

In the image below, the Y scale has worked OK, but the X scale is compressed.

I tried the "World Scale UV" tool of the 'Magic UV' add-on (suggested in a similar question), but I couldn't get a useful result from that.

All transforms and scales have been applied. I don't know if it's relevant, but the original geometry has been created via geometry nodes and modifiers that have since been applied.

[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/AV1bD.png

I've attached the blend file from the image above for reference.

[<img src="https://blend-exchange.com/embedImage.png?bid=O6za55yA" />](https://blend-exchange.com/b/O6za55yA/)

**EDIT**:It just occurred to me that my model isn't directly on the XZ or YZ plane, so the UV wrap could just be a projection of the faces to one of those planes - is that the case?