8 1/2" straight arm Getty metal casement operator

Dear Sirs,

I am restoring a protected landmark house in Houston. It was built in 1935 and has metal casement windows that I am required to restore. They have 8 1/2" straight arm operators with 4 screw holes (4 3/4" spacing on outside screws and 3 7/8" spacing on the inside pair.

They are half round bodies with brass handle on the end of the arm (see attached photo).

Do you know where I can purchase replacement operators? Even if they don't look exactly the same but will operate.

Thank you for any assistance that you can provide.

I ordered the 39-045 and everything about it worked except that the window wouldn't fully close due to the legnth of the arm hitting the rivet at the end of the window track. Is there a shorter version (shorter than 8 1/2")? If it was shorter than 8 1/2" it should open and fully close without modifying the track on the window.

Thanks again for any help that you can give me.