Hi everyone!

I found this 1957 signed Princess Grace/Grace Kelly letter for sale, and I would appreciate any comments on its authenticity.

This letter was sent by Princess Grace to a shoe store in Spain, thanking its owners for sending her 4 pairs of shoes for her newly born daughter, Princess Caroline of Monaco.

Could this be a forgery, secretarial or autopen? Or does it look ok?

Thank you very much, as always, for your help and support!