Acorn slide up window parts

I have a client with Acorn slide up windows and need replacement parts for same. I have attached pictures of the tilt out side rod mechanisms and I see on you web page similar rod mechanisms but no similar nylon bottom pieces that the pivot pins on the window can fit into. The rods measure 29" and are 1/2" in diameter. Do you have replacements for these? I need at least a right and left for one window and I would probably order an extra set for future use if another window needs them later on.

I remeasured with calipers and at .550 I could call it 9/16 but not 5/8". I wouldn't care as long as it fits in the cavity and works with the pivot pins on the tilt out window. Do you still think the 600 series or something else? The aluminum rod measures 29" long and in the pictures the center one is showing the pivot shoe broken into two pcs. (the part broken off is on the window sill in the left picture. Whatever is your best guess I will buy and try since I have no other way to go as far as I can tell.
Thank you very much for your response.
Phil