The first thing to point out here is that the case, of course, is not included. Of the image above the 5 pieces of black padding inside the case is what we are concerned with.
Gewa, like most manufacturers, do not produce a 7/8 size cello case. This padding then, although niche, is the solution. You can purchase a case for a full size instrument whilst creating an interior which fits the smaller instrument snugly.
The padding itself comes in 5 parts and is produced from what the manufacturer call 'Black warp pile velvet'. Whilst it is soft it provides a firm enough backing to hold the cello in place.
Each of the 5 parts is specifically shaped to fit into the correct part of the cello case and it is this which makes it so much better than anything home-made.
It is ideal for cellos which are slightly smaller than what we would today call full size.