Patio door handle missing locking mechanism

If all you need is the thumb lever, you could consider our 82-252. I cannot confirm if this is a match since I can't quite make yours out, but it may be our only option. 

The OX indicates how the door operates when outside. X is the moving panel and O is the stationary panel. This appears to be how your door operates but you may want to double check in case I'm mis-reading your photo.