First off, I would use various sized shims such as matches pieces of cardboard etc. and test fire until I found the proper height.
I would then locate a piece of sheet steel of the right thickness and go ahead and make one. A step or two either side of the selected height would be ideal. Using a file on a thin strip of steel is a rather simple task. A little sanding, buffing, bluing and.. wallah; satisfaction in a job well done..an act of self-sufficency.
A little taper toward a notch will help to retain the elevator. Below, see method of measuring correct height and the shape to file the elevator. Notice each step is angled to form a notch, so the elevator will stay in place. I also showed a notched thumb-grip area to slide the elevator with. Before finishing take it to the range with a file and do "final" adjustments...may work better than a factory "will fit".
Keep in mind, the notch and thus the height measurement should be dirtectly under the v ertical sight blade.