I really like the 1912 model of the Steyr so I have decided to make it possible to 3d print one yourself. Most of the parts were resized a bit to fit better but the main frame remains unchanged so the size is accurate. 

If you want to add springs the sizes are as follows:

1. 18.7 x 5.4mm (firing pin(not vital for operation))

2. 85 x 9mm (slider)

I have also included the .f3d and .stp files for ease of assembly.