Arlene......I have one that I did for my hubbys best friend.....he had a stroke and this is what he rides now......don't know if it will be a fit for you, but here is a link to it..........Vicki
It goes to show you, sometimes you need only look in your own neighborhood to get exactly what you need! Yeah!
Well, I Googled Tricycle Embroidery Designs...lots of tricycles, but not sure any of them would do for an adult tricycle...might be worth a look though if you haven't already checked them out...
Wow! Hard to believe you have discovered an embroidery design that doesn't seem to available anywhere! Maybe you should suggest this design to some of the companies that digitize and sell designs. Seems there would be a market for it since the trikes are being sold everywhere now.