Searching for 25 year old pella sliding doors with internal shades between glass panels. The shade control in lower right corner is broken on 5 doors/windows

I have a sun room with Pella windows and sliding doors--about 25 years old. Two of the doors and three of the windows have blinds that turn inside two glass panels.

Each of the controls, which are found in the lower right hand corner, of each door/window are broken and will not turn the blind.

Thus I need 6 replacement parts as shown in the photo

Thanks