I was unable to find any mention in your letter for the provision of royalties. Since you are selling my son's work to others, it is normal that he should expect some nominal entitlement to accrue. I also read with interest the form that must be signed by the parent or guardian of the child. This certifies that the story is an original work and that my son is the sole copyright owner. I congratulate you on your caution in this matter.
Children are instinctively post-modern in their creative approach.
Heaven forbid that you should find yourself at the receiving end of a legal action with the estate of Enid Blyton or the Disney Corporation or somesuch as a result of your kindnesses. My son does not have the wherewithal to pay damages but my signature on the form will provide access to assets which will cover that contingency. Finally, may I say how impressed I was by the production quality of your correspondence. I can remember 20 years ago how pathetically unconvincing form letters used to be. It seems that nowadays home computers are so powerful that you can mail letters to thousands of people in such a way that they seem to be seamlessly personalised.