I have considered making my own rails using a laser cutting service. I have done this before where I created 500 mm to 19 inch rack adapters and had them laser cut at lasergist.com. Fairly simple really, just make a drawing in Fusion360 and upload the drawing. A few days later the adapters arrived.

Rails would probably require some metal bending but could otherwise be made the same way. Maybe we could do an open source design here?

Regards

Baldur