cases for violins (New Marston OX3)

I'm still restoring and rehoming unloved violins and will have a few of them to give away, but the limiting factor at the moment is cases. Many of the instruments arrive here with no case or in an ancient cardboard/paper thing that offers no real protection. So I'm looking for the standard polystyrene cases that you get as part of the package when you buy a student violin these days, eg the Stentor or Primavera models (two typical Stentor cases shown in the photo). As some people like to replace that standard case with something fancier, I am guessing that there must be quite a few of the standard ones sitting around in garages and attics? I mostly handle full size (4/4) violins, so could use any number of 4/4 cases. One slightly oversized violin is also in search of a case. And one cello! All other string accessories and indeed broken instruments also welcome. Can collect in cycling distance, ie roughly within the Oxford Ring Road.