The Case Of The Greystone Inscription is a Sherlock Holmes television movie from 1955.
It stars Ronald Howard as Holmes, H. Marion Crawford as Dr. Watson and Archie Duncan as Inspector Lestrade.
A professor in the making is on the verge of a discovery and he tells his fiancé that he has to go to Greystone Castle, in Scotland.
He doesn’t return so she visits herself where they deny knowing who he is.
She then finds a note from her fiancé in the bushes outside so turns to Holmes to help her.
He solves the mystery and it ends with a personal letter of thanks from Queen Victoria.
Movie pages here.