You could even take a regular 3/4 or 19mm and just grind it thin enough. Just keep quenching it in wTer to keep from overheating it. I used to own some logging equipment and I had my good wrenches and also a cheap set for bending into odd shapes and cutting the heads off and welding them back on at different angles etc.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.