LWD parts:
https://www.lwdparts.com/product/shell-assy-cylinder/
You could enquire if they have the other components, but I would also try Brian Ashbury.
I think the Plate 4.9042 and the Hook Bolts 4.9283 could be readily fabricated (plate) or adapted (Hook Bolts) once you have the Cylinder to give you dimensions. Just leaves the spring to find.