my answer from yesterday, bottom of page
I left an answer yesterday but it disappeared. My suggestion was to do a regular one on felt and trim around the edges.
Hummm, I haven't seen one either but can you take a regular taxi cab design and embroider it on organza or netting then trim the fabric away to make them like a patch? Maybe someone else can advise you on this. I'll move it to the top for you.
I haven't seen one. But I will keep my eyes peeled for one! Dawn