Casement Operator, need covers and handle

I'm having a hard time making out what you have. Would it be possible to see a picture of the cover and handle in one shot? Many details are obscured in your photo. 

In the meantime, see our 39-375 and 39-376 and see if you could use either of these. They are both a cover/handle combo made for Truth brand operators. The spline is 11/32" in diameter, though I'm not sure what the diameter of your spline is.