So here goes. . .
Peter O'Toole - (1932)
played a part in the Walt Disney's 1960 version of 'Kidnapped' -
which featured the posthumous Oscar winning actor Peter Finch (1916-1977)
who had a part in the sequel to one of my favorite films,'Mrs. Miniver', 'The Miniver Story' - 1950
which featured legend Reginald Owen (1887-1972)
who not only played Watson in 1932's 'Sherlock Holmes'
but also played Sherlock Holmes the following year in 1933's 'A Study in Scarlet'
So there you have it, there you are.
P.S. and as James pointed out, and a quicker way to a connection, O'Toole voiced Holmes in cartoons in the 1980's.
So, this time, there you have it, there you are.