Non Standard 20 inch Greenhouse Glass (Corringham SS17)

I have around 18 of 18 x 20 inch greenhouse glass, and 7 of 20 x 20 inch panes. 20 inches = 508 mm and 18 inches = 457mm

I will never use 20 inch wide glass with the frames that I have. So they are free to anybody that can use them in a project. As they have been sitting in my shed for decades.

Standard British greenhouse frames take 24 inch/610 mm wide glass. So I suspect these came from an imported greenhouse decades ago.