Need part number and cost

It appears that you have an older-style awning operator. We do not carry this brand and I'm not sure that it is still available. I honestly don't believe it's been made in years, though I don't know it for a fact.

Either way, look at the 39-083 operator. This appears to have the same size arms as yours but the overall design is still different. I don't know if this will work but if it can it will likely take some measure of adaptation, specifically of the sill and sill trim. You may want the help of a local professional on this.