Thank you! I have been doing what you suggest; but I’ll see if I can track down Theobold’s. You never know!
Just to clarify, I DO have the standard overlocker foot with the machine, and I can overlock with it—so no need to return it!
But it is supposed to have an additional overlocker foot, for doing a rolled hem. This is one I don’t have. I’m hoping that someone who has the machine, but doesn’t use the rolled hemming function, might just be willing to sell me the spare foot...