Need replacement for balcony slider internal lock mechanism

Hi,
The latch on our slider(circa 1980) broke off. I can't find a manufacturer or any numbers on the sliders. The approximate dimensions of the piece are 6.5" L x 1" D x 1.25" W. I went to three hardware stores and no luck. See attached photos and let me know what you think.

Regards,

Heather

One more photo of what the exterior of the handle looks like on the door adjacent to the broken one. The lock latch broke off and we can't lock the door. See additional photos on my original request.