Casement window operator linkage says Del Mar Toronto with the number 21550 stamped on it.
A handy person from Alpharetta, GA says:
April 11, 2018
Thanks for your response...Here are some pictures, I have not disassembled the operator but if it helps I can take measurements. Thanks!
Tom from SWISCO responded:
April 16, 2018
Based on your pictures, I'd start with our 39-317 and 39-318. These appear similar in style to your operators. Look over our photos and dimensions and let me know what you think!