Hello again,
I decided to do this to them, which I suppose classes as my first ever leather project. I have quite a bit of this leather lying around and I haven't done anything with it. Its like car upholstery leather. I made the mistake of sewing the gaps in the canvas just a little bit too small (I suggest more than 5mm if anyone gets any ideas on this) but it will do for now, and the canvas has a little bit of give in it anyway. This has made the leather on the outside go wrinkly but oh well.. I attached a strap in the middle of the long side and just wrap it around to close it up. Now it can sit safely somewhere when I have to pack things away and there is enough space on the long leather side to sew another row of canvas holder if I acquire more stamps. I don't think it's too bad for a first effort, and don't look to closely at the stitching - my treadle machine was throwing wobblies today.
Now to use them all!
Cheers